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Vietnam Marine & Offshore Expo, Nov. 19-21
The Vietnam Marine & Offshore Expo will take place November 19 to 21, 2025 (VIMOX 2025) at the Adora Cente in Ho Chi Minh.
Vietnam is ranked fifth globally in shipbuilding and is a key maritime hub in Asia.
The event will bring together leading international companies and industry experts to showcase cutting-edge innovations and sustainable solutions in shipbuilding and maritime industries. VIMOX 2025 will also feature a collaboration with Offshore Wind Vietnam Expo to drive innovation, foster business connections and promote the future of sustainable maritime technologies.
Highlight of VIMOX 2025 include:
- Shipbuilders Pavilion: a dedicated space showcasing top shipbuilders and maritime
suppliers. - Networking lunch for ship builders and shipowners: exclusive opportunities to connect
with key industry players. - Shipyard facility visit: a behind-the-scenes look at Vietnam’s leading shipbuilding
facilities. - Maritime conference: featuring expert discussions on industry trends, challenges and
opportunities. - Shipbuilding and maritime technology seminars: exploring the latest advancements
shaping the industry’s future.
Farewell from Sea Technology
Sea Technology Publishers Charles H. Bussmann (Left) and Amos C. Bussmann (Right)
To the Sea Technology community:
We have tough news: After 62+ years in business, ST will cease publication permanently. October 15 is the final day of operation.
The website will remain live until October 2026. The digital archives will be available through the site during this period.
We want to thank all of you for your support and engagement over the decades. You have been invaluable, and it has been our pleasure to serve this community.
–The Sea Technology staff
Case Study: Coral Bleaching in Mauritius
By Dr. Anusha Devi Nawoor • Dr. Nora von Xylander
Coral reefs are among the most diverse and valuable ecosystems on Earth. These vibrant ecosystems support more than 30 percent of marine biodiversity, providing essential ecosystem services that sustain more than 500 million people worldwide and contribute an estimated global economic value of approximately $10 trillion per year.
These ecosystems face a constant threat from coral bleaching. Coral bleaching occurs when stressed corals expel the symbiotic algae (zooxanthellae) that resides within their tissues. This not only robs them of their vibrant colors but also deprives them of their most essential source of energy, making them susceptible to starvation, disease and mortality.
The primary driver of coral bleaching is marine heatwaves caused by climate change, with high light intensity and rising sea surface temperatures (SST) acting as major stressors. The frequency and intensity of marine heatwaves have increased in recent decades, resulting in more frequent and severe coral bleaching events on a global scale. In 2015, the world experienced a third global coral bleaching event. During this period, maximum heat stress levels reached Alert Levels 1 and 2, indicating prolonged exposure to temperatures ≥ 4 to 8° C above normal per week, a threshold known to trigger mass bleaching.
NOAA reported the fourth global bleaching event at the start of 2024. This unprecedented event comprised record-breaking SSTs, with values exceeding 20° C heating weeks in several locations across the Indo-Pacific. The severity of this event forced NOAA to introduce two new bleaching alert levels (4 and 5), as previous scales were insufficient to capture the extent of coral loss. Alert Level Five signifies near-total mortality.
At present, the full extent of the fourth global coral bleaching event remains uncertain, but what is clear is that inaction is not an option.
Case Study: Mauritius
Coral bleaching is a major concern for Mauritius, an island nation in the Indian Ocean that reies heavily on its coral reefs for coastal protection, marine biodiversity and tourism. The rise in ocean temperatures and increased frequency of coral bleaching events due to climate change has increasingly affected local reefs.
The rising SSTs, particularly during El Niño and positive Indian Ocean Dipole events, have triggered severe bleaching in Mauritius (i.e., 1998, 2006, 2016 and 2024), with even small anomalies (≥1° C) causing mass coral bleaching. Since 2003, SSTs around Mauritius have risen by 0.16° C per decade, surpassing the bleaching threshold of 27.5° C and diminishing coral fitness. Ocean acidification (OA), driven by increasing CO₂ levels, further compromises reef resilience. Declining pH levels at sites such as Bel Ombre, Bambous Virieux, and Trou aux Biches may reduce calcification rates and impair reef formation, affecting not just corals but all calcifying marine species. Rising sea levels in Mauritius, which averaged 3.8 mm per year from 1987 to 2014, further amplify coastal erosion and flooding. These changes impact shallow fringing reefs due to sediment shifts and changes in tidal dynamics. Cyclones present a double-edged sword. While they can reduce thermal stress through water mixing, they also cause mechanical damage, smothering corals with debris and sediments. As cyclone frequency and intensity increase, the damage to already stressed reefs becomes harder to reverse. These stressors create damaging feedback loops. Bleached corals become more susceptible to disease and algal overgrowth, especially in overfished and nutrient-rich areas. Dead coral structures are quickly colonized by algae, further hindering recovery. Sediment and pollution exacerbate these effects, while predator outbreaks such as crown-of-thorns starfish (COTS) delay natural regeneration. The interplay between these climate stressors combined with local human activities, such as coastal development, agricultural runoff, and fisheries pressure, further weakens coral reefs and inhibits their recovery.
Mauritius: Coral Bleaching History
Mauritius experienced its first recorded mass coral bleaching in 1998 during the strongest El Niño on record, when SSTs rose by 1 to 1.5° C, disrupting heat-sensitive zooxanthellae and resulting in bleaching corals. Mortality was generally below 10 percent at most sites, with the highest bleaching (38.6 percent) in the south at Le Bouchon. The comparatively low impact, especially compared to >90 percent mortality in parts of the Seychelles and Maldives, was attributed to cyclonic activity cooling surface waters and reducing solar exposure. Vulnerability was greatest in shallow, poorly flushed lagoons, while deeper or well-circulated lagoons had higher survival.
In January 2005, reef surveys at Ile aux Aigrettes, Flic en Flac, Grand Baie, and Bel Ombre found live coral cover generally under 5 percent at most sites, except Bel Ombre, which had nearly 100 percent cover and high species diversity. Key threats included: nutrient pollution, algal overgrowth, cyanobacterial mats and predation by COTS. Recommendations included: improved wastewater treatment, effluent reuse, coral restoration, shoreline protection and long-term monitoring. By April to May 2006, monitoring showed recovery from the 2005 bleaching, with most sites returning to pre-bleaching conditions, except Totor in northern Rodrigues, where 15 percent standing dead coral, turf algal dominance, and limited coral recruitment indicated impaired recovery.
During the third global bleaching event in 2016, Mauritius was again less severely impacted than some other Western Indian Ocean nations. Thermal stress began in mid-December 2015, peaking at 16° C heating weeks between late March and May 2016. Over 40 percent of corals were partially bleached, with severe impacts (more than 65 percent affected) at Belle Mare, Flic en Flac, and Île aux Bénitiers, while Blue Bay, Bel Ombre, and Mon Choisy experienced less than 15 percent bleaching. Severe bleaching peaked in March to April, with about 35 percent of observations reporting more than 50 percent bleaching, but mortality was low at monitored sites, such as Anse la Raie Lagoon, where coral cover remained stable (approximately 35 percent) from 2013 to 2017. The absence of a national post-event survey limits the accuracy of mortality estimates, particularly for Rodrigues, where losses were reportedly high.
The 2024 global bleaching event, driven by a strong El Niño and positive Indian Ocean Dipole, brought severe thermal stress to much of the Western Indian Ocean. In Mauritius, bleaching was reported as moderate, with some sites showing medium to high severity, though data submissions were fewer compared to neighboring countries. Regionally, 73 percent of observations showed moderate to severe bleaching, and 9.9 percent of reefs experienced high mortality. While site-specific mortality data for Mauritius remain limited, approximately 80 percent of reefs in the region were affected, underscoring the urgent need for ongoing monitoring, targeted conservation and climate adaptation measures.
Outlook for Coral Reefs in Mauritius
The reported coral bleaching events have brought Mauritius’ reefs to a tipping point. While isolated signs of resilience persist, compounded impacts from warming seas, pollution, and coastal development continue to undermine reef recovery. Without sustained intervention, Mauritius risks losing its reefs’ critical ecosystem functions. In response, Mauritius is actively working on a range of coral reef conservation initiatives focused on restoration, community engagement, policy and technology. Key efforts include the Tech4Nature initiative (Huawei and IUCN), which uses nursery-grown coral fragments and real-time monitoring to rehabilitate degraded reefs, and the Adaptation Fund, a program aimed at selecting heat-tolerant corals to restore climate-resilient reefs in Mauritius and the Seychelles. Community-based coral culture projects, led by the Mauritius Oceanography Institute and the Nairobi Convention’s WIOSAP, train locals in reef restoration while supporting sustainable livelihoods. The establishment of marine protected areas (MPAs), such as Anse la Raie, and the use of digital monitoring tools strengthen current efforts. These combined strategies are critical to enhancing the resilience of Mauritius’s reefs in the face of escalating climate pressures.
However, local and global stress factors attacking Mauritius’s coral reef system must be comprehensively assessed and optimally managed for the sustainability of reefs. Natural sources such as cyclonic conditions have occasionally helped to lessen the bleaching to some extent, but constant anthropogenic impacts make recovery challenging. Higher carbon emissions and consequently higher global temperatures require immediate intervention to reduce the effects on and promote the successful adaptation of corals.
Without addressing root causes, the survival of coral reefs worldwide remains at serious risk. To secure long-term reef resilience, local measures must be paired with more global science-based restoration efforts and urgent action on climate change. Mauritius’s reefs reflect a broader global trend: recovery windows are narrowing, and without transformative change, future bleaching events may push these fragile ecosystems beyond their capacity to recover.
Dr. Anusha Devi Nawoor is an environmental scientist at Tunley Environmental.
Treasures, Shipwrecks and the Dawn of Red Sea Diving
By Howard Rosenstein
My diving career had a unique beginning. In 1968, at the age of 21, while skin diving off the ancient Roman harbor of Caesaria along Israel’s Mediterranean coast, I noticed something glittering on the seabed. Freediving down to investigate, I picked up the shiny object, along with a handful of sand. As I surfaced, the sand filtered through my fingers, leaving in my palm, a 2,000-year-old Roman gold coin, the first of many I would find over the next few years. With money from the sale of some of these coins, I started my diving business in 1970 at the age of 23.
By 1972, my Mediterranean Diving Center had become successful, and I decided to open a branch at the oasis resort of Neviot beside the Red Sea on the Sinai Peninsula. A year later, I relocated to Na’ama Bay in Sharm el Sheikh, Egypt, in the southern Sinai.
The road from Eilat to Sharm el Sheikh along the Red Sea was completed in 1972, the year I began my business. The Sinai at the time was a remote, isolated place, populated by Bedouin communities and several hundred Israelis, some of whom helped establish tourism-based settlements in Nuweiba, Dahab, and Sharm el Sheikh.
Throughout history, the Sinai Peninsula has been a battleground between regional powers, most recently, between Egypt and Israel, with major wars in 1956, 1967, and 1973. When we started our diving operations, remnants of these conflicts lay scattered throughout the landscape, in stark contrast to the area’s beauty above and below the Red Sea waters. We used to gear up in the shadow of abandoned Egyptian tanks on the shore next to Ras Muhammad National Park as late as 1974.
In the early 1970s, conditions were basic, and simple accommodations and limited tourism infrastructure characterized the holiday experience. The first customers to dive with us in the Red Sea were students and certified divers from our Mediterranean Diving Center/Red Sea Divers, as well as local dive enthusiasts.
My business got its first big break when National Geographic ran a cover story by Dr. Eugenie Clark, with photography by David Doubilet, featuring our diving operation in September 1975. That article and additional media coverage helped attract divers initially from Europe, later from the U.S., and eventually from all over the world. The business continued to grow.
2,000-year-old Roman gold coins.
When we started, all dive sites were virgin, with many sites easily accessible from the shore via small boats. We were among the first lucky ones to discover, explore and share them. With so few diving operations in the area, our divers and staff had most of the sites to themselves, something hard to fathom these days, when it’s common to have tens of dive boats moored over the more popular dive sites.
When Egypt took control of the Sinai in April 1982, there was only one hotel, three diving operations, and fewer than 10 dive boats in Sharm el Sheikh. Live-aboard diving safaris were introduced in the early 1980s, and I expanded into this activity.
During my 50 years in the diving business, I have had many memorable experiences. One of the most unusual was a dive down into an ancient Bedouin well at Saint Catherine’s Monastery at the foot of Mount Sinai. The purpose of the dive was to extract a broken water pump damaged in a flood. My dive was down a 20-m-deep well at an altitude of 1,500 m. I had never dived at altitude and was totally unaware of the decompression effects. While diving into a dark hole in the earth at the foot of Mount Sinai, I got tangled in the wires and pipes of the pump and was barely able to extract myself and emerge with the pump. I succeeded–but I almost lost my life in the process.
In the early 1970s, with all the incredible diving in the Red Sea, one diving attraction was missing: a shipwreck. We tried for years to find one, and then, one day, a local Bedouin fisherman hinted at a wreck out in the Suez Gulf, beyond our usual expedition area. Our search led to the discovery of the wreck of the SS Dunraven, a British steamship that ran aground in 1876 and sank at the Sha’ab Mahmoud Reef. There is nothing more thrilling than finding a virgin wreck, lying untouched on the seafloor for 100 years.
Over the past half-century, the Sinai has become one of the most sought-after dive destinations in the world, with tens of thousands of divers and hundreds of dive boats. There is stringent conservation policy, first instituted by the Israeli administration in the 1970s and followed by the Egyptian administration. But the significant increase in diving activity and the construction of large hotels and resorts along the shore has affected the quality of diving, with the pelagic fish and sharks much less evident than in the early years of Sinai diving.
The Red Sea region has been plagued by geopolitical and security challenges ever since we started our operations. The 1979 peace treaty between Israel and Egypt ushered in a new era for Sinai diving, leading to continued, though uneven, increases in business. Whenever the region was clouded in conflict, business would drop dramatically. Yet, somehow, the area rebounds; the tourists return, and business flourishes again, at least until the next round of conflict.
I managed to operate in this climate for 25 years, but, ultimately, due to political tensions, it became too risky and challenging to run the type of high-end operation that we had established. I closed my live-aboard business in 1997.
Diving the Red Sea during the pioneering period of exploration was among the very best years of my life.
Howard Rosenstein’s memoir is available at www.olympusdive.com and Amazon.
How Hydrogen Technology Supports the Energy Transition
An overview of the considerations when developing green fuel projects.
By Richard Colwill • Alexander Tancock • Warner Priest
Shipping is faced with a supply problem, not just the perpetual concerns about suitably qualified and experienced personnel, or container supply and distribution, but also a new challenge on the near horizon. The measures agreed upon at the April 2025 International Maritime Organization Marine Environment Protection Committee meeting (IMO MEPC 83) require a transition to low-carbon fuels that may not be available in the quantities needed to meet future emission reduction targets.
The MEPC 83 agreement, when formally adopted in October 2025 as expected, will chart a course for international shipping that requires the use of lower (LNG or e-methanol) or zero (blue or green ammonia) carbon-emission fuels. Modeling of the future MEPC 83 landscape suggests that from the mid-2030s ammonia is likely to be the least-cost option, either of the “blue” (where carbon is sequestrated) or “green” (developed from hydrogen electrolysis, powered by renewable energy) variety.
It’s worth noting the basic time scales involved in the emerging fuels market: Developers seek 10- to 15-year offtake agreements with the shipping industry. Meanwhile, the shipping industry takes three to four years to build a vessel for a 25-year operating life, while eight to 15 years are required to create major supply for a 25- to 50-year investment period.
“The development of the value chain for e-fuels cannot be delayed until the late 2030s if it is to reach technological and commercial viability in time for full scale up,” according to the Getting to Zero Coalition maritime forum.
Project Development
InterContinental Energy was created more than a decade ago to address the fundamental questions of where the large-scale renewable energy sites of the future should be located and how they can be developed. The company recognizes that if a significant proportion of fossil fuel were to be displaced globally, then renewable energy sites of significant scale would be required to support direct electrification and e-fuel creation. This global search requires assessment of: wind and solar resources; population distributions; environmental values mapping; and industrial and project capability.
Three initial projects have been developed from the initial global assessment, focused on remote coastal desert sites: the Australian Renewable Energy Hub (AREH) in Western Australia; the Western Green Energy Hub (WGEH) in Western Australia, in partnership with the Mirning Traditional Owners; and Green Energy Oman (GEO) in Oman, in partnership with Shell.
The InterContinental Energy portfolio represents some of the largest and most ambitious projects in the world. Yet, the targeted capacity of 8 million tonnes per annum (MTPA) of green hydrogen production to be brought online between 2035 and 2050 is only a small portion of the current bunker fuel market, which is around 250 to 300 MTPA. Successful development of many other projects worldwide will be needed to meet global demand for e-fuels—of which the maritime industry will be only one customer.
The key steps for e-fuels project development include: site selection, with an overview of opportunities and constraints; resource validation, including wind and solar monitoring; land negotiation with government and traditional owners/users; environmental impact review; engineering to define, develop, and deliver viable concepts; and offtake agreements to develop fully bankable projects.
These steps are similar to large-resource oil and gas projects, particularly the establishment of the LNG industry. However, the e-fuels industry is new, and while its protagonists may be traveling a well-trod path, there is a requirement to educate authorities, regulators, stakeholders, and investors on the opportunities and challenges of this new industry.
InterContinental Energy is now well along this path, with projects set to receive final investment decisions by/around the 2030s that will ensure large-scale supply from the mid-2030s onward. Such projects will provide key stability for the marine industry, where fuel volatility in the last three years has seen very low sulphur fuel oil pivot between $500 and $1,100 USD per tonne. Development of such e-fuels projects allows customers to lock-in fuel price with zero-carbon characteristics for the long term, making shipowners future-proof against anticipated tightening of emission standards.
The P2(H2)Node system co-locates giga-scale hydrogen production with wind and solar farms. At scale, the resulting fuel will contribute to the maritime energy transition.
The Opportunity and Challenge of Scale
While large projects, such as InterContinental Energy’s AREH, WGEH, and GEO, offer the opportunity to meet the demands of the marine industry at scale, they have intrinsic challenges and tensions. There is a gap between how the first phase of a project can be credibly and competitively developed and the best arrangement of the final project to deliver maximum competitiveness.
This gap is linked to investments that are made in overcoming initial logistical and economic hurdles associated with scaling supply chains, optimizing production costs, and addressing storage and transport challenges.
To tackle these issues, InterContinental Energy has developed the P2(H2)Node. Just as standardized shipping containers revolutionized the global shipping industry, the P2(H2)Node’s standardized architecture could streamline the green hydrogen industry by replacing bespoke projects with a uniform architecture. Removing complexity and increasing repeatability will ensure all projects can access the lowest cost of production.
Conventional centralized models require expensive electricity transmission, leading to energy losses and inefficiencies. The patented P2(H2)Node system flips this model by co-locating giga-scale hydrogen production with wind and solar farms, ensuring power is used where it’s generated and the highest power efficiency and least-cost fuel product can be obtained, within a development model that permits expansion to meet shipping’s significant future demand.
Key advantages of the P2(H2)Node architecture include: up to 10 percent less CAPEX through standardization, modularity, reduced electrical infrastructure, and reduced storage requirements; up to 10 percent more efficiency through design optimization and elimination of very-high-voltage power equipment; and built-in energy storage to allow for more consistent flow delivery to customers via line packing of hydrogen pipelines.
Taken together, this system lowers production costs by 10 to 20 percent; builds sustainable supply chains; and will enable faster large-scale hydrogen adoption for industries such as green iron, fertilizers, global shipping, and aviation fuels.
Pioneering Hydrogen Hub
Showcasing the early development of hydrogen production, the P2(H2)Node architecture serves as the backbone of Australia’s groundbreaking Western Green Energy Hub (WGEH), set in the southeast of Western Australia. This project, which may ultimately expand across 22,000 km2 of tableland, will be developed in multiple phases to match demand for green hydrogen and ammonia exports.
Its scale, with ultimate buildout to 28 MTPA of green e-fuels capacity, positions it as the world’s largest and most cost-efficient green e-fuels hub. With the support of newly announced Australian government hydrogen incentives, WGEH is projected to drive down production costs for green ammonia below $650 USD per tonne from the mid-2030s, unlocking competitive zero-carbon fuel provision. This ability to provide large volumes of competitively priced e-fuels is a key part of the puzzle as the marine industry seeks to navigate the challenges of long-term vessel and bunkering investments.
P2(H2)Node architecture is the backbone of Australia’s groundbreaking Western Green Energy Hub.
Conclusion
The bunker fuel market is on the cusp of a major transformation as a result of the MEPC 83 agreement; however, this transition depends on scalable, cost-effective production of alternatives, particularly the development of fully “green” e-fuels developed from renewable energy.
InterContinental Energy’s development of an extensive project portfolio and the P2(H2)Node solution offers a global, scalable, cost-efficient model for providing green molecules to the hard-to-decarbonize, heavy-industry marine sector. Such initiatives and the support of far-sighted investors and customers will be instrumental to ensure a sustainable and efficient energy transition.
Richard Colwill is the head of engineering and innovation at InterContinental Energy.
Alexander Tancock is the CEO of InterContinental Energy.
Warner Priest is the midstream director at InterContinental Energy.
World’s First Full-Scale CCS Deployment on a Seagoing Vessel
Wärtsilä’s onboard CCS technology is installed aboard Solvang ASA’s ethylene carrier Clipper Eris. This is the world’s first full-scale CCS deployment on a seagoing vessel, designed to capture more than 70 percent of carbon dioxide from all onboard combustion sources.
By Sigurd Jenssen
Shipping is at a crossroads. It moves more than 80 percent of global trade, yet it produces around 2 percent of global greenhouse gas emissions. Without intervention, those emissions could rise by as much as 45 percent by 2050, even as other sectors decarbonize. The International Maritime Organization (IMO) has set clear milestones: a 20 to 30 percent reduction in emissions by 2030; 70 percent by 2040; and net-zero by 2050. The EU has added its own measures, including the Emissions Trading System (ETS) and FuelEU Maritime, that place a direct price on carbon.
For shipowners, carbon-neutral fuels, such as green methanol or ammonia, remain expensive and scarce, with supplies unlikely to meet full industry demand for at least a decade. Against this backdrop, Wärtsilä’s onboard carbon capture and storage (CCS) technology offers a proven pathway to slash emissions today. Installed aboard Solvang ASA’s 21,000-cubic-m ethylene carrier Clipper Eris, this is the world’s first full-scale CCS deployment on a seagoing vessel, designed to capture more than 70 percent of carbon dioxide from all onboard combustion sources.
How the System Works at Sea
Wärtsilä’s system comprises several stages or modules: exhaust gas pre-treatment, chemical absorption, desorption, liquefaction and storage. These stages can be tailored for different fuel types and capture rates. Exhaust gases from the main and auxiliary engines, as well as the boilers, are cooled and scrubbed to remove SOx, NOx, and particulates, achieving reductions of over 97, 80, and 90 percent, respectively. The cleaned stream enters an absorber tower, where an amine-based solvent captures the carbon dioxide. This blend was selected for its stability across fuel types, low degradation rate, affordability and global availability.
Once saturated, the solvent passes to a desorber, where captured CO2 is stripped using heat recovered from the ship’s systems to reduce additional fuel burn. The stripped CO2 is compressed, liquefied, and transferred to onboard tanks; in Clipper Eris’s case, two 360-cubic-m units mounted on deck to avoid cargo disruption. This configuration supports roughly 14 to 20 days of operation before offloading. The system handles up to 50 tonnes per day on Clipper Eris, with Wärtsilä’s Moss, Norway, test center confirming 10 tonnes per day under controlled conditions.
The installation connects to every combustion source on board, the 7,100-kW main engine, auxiliaries, and boilers, without requiring modifications to the prime mover. Operational results have shown consistent capture rates above 70 percent during typical voyages and peaks exceeding 90 percent during low engine loads. Energy integration has been a critical part of the design. Total electrical demand equates to roughly 8 to 10 percent of propulsion power: 3 to 5 percent for the carbon capture processes and 6 to 8 percent for CO2 liquefaction. Thermal demand sits at around 35 percent of the capture cycle’s energy needs, largely offset through heat recovery systems. Engineers continue to refine solvent formulations and heat integration to lower this figure, with ongoing testing at Moss aimed at extending solvent life and further reducing parasitic loads.
Wärtsilä’s Moss, Norway, testing facility has validated the system under more than 5,000 operational hours, trialing multiple fuel types, including heavy fuel oil and marine gas oil, as well as simulations of exhaust from LNG and methanol, to confirm solvent stability and capture efficiency across a range of load conditions. Testing also validated tank insulation standards designed to prevent boil off during extended voyages, which is critical for operators trading globally who may not discharge CO2 for several weeks. Solvent degradation rates have been kept under control by reclaim systems that filter contaminants and recycle usable solution, extending operational life and lowering consumable costs over time.
How a carbon capture system works.
Engineering and Design Challenges
Unlike industrial carbon capture systems, which benefit from stable flows and unlimited space, maritime CCS must operate within compact footprints and variable conditions. The absorber towers on Clipper Eris use a counter-current packed column design, where upward flowing exhaust gas meets downward flowing solvent over structured packing that maximizes contact area. This configuration ensures high capture efficiency even as exhaust characteristics change between heavy fuel oil, LNG, and methanol operations. The tower’s internals are fabricated from corrosion-resistant alloys.
Liquefaction follows a staged compression process, stepping CO2 up to storage pressure before cooling to roughly -26° C. Each stage recovers heat for reuse elsewhere in the system, cutting electrical demand. Automated controls balance compressor loading and heat integration dynamically, so energy use remains proportional to capture volume. Crew monitoring is simplified by integrated dashboards showing solvent levels, capture rates, and tank fill status, enabling operators to maintain performance through routine checks rather than constant oversight. Filtration and reclaiming systems extend solvent life, reducing the frequency of top ups and waste generation.
Wärtsilä’s system is built to cope with the realities of life at sea. Skid-mounted absorber and desorber units are reinforced to handle constant vibration and ship motion, while flexible piping and shock absorbing supports limit stress on key components during heavy seas. Fluctuating CO2 concentrations in exhaust streams, caused by changing engine loads, are addressed through adaptive automation that adjusts solvent flow rates and desorption energy input in real time, keeping capture steady. Crew involvement is kept to a minimum by intuitive interface that consolidate key data, enabling quick decisions without specialist training. These design choices make continuous CCS operation feasible even for vessels with small crews and long voyages. Wärtsilä’s approach also allows systems to be broken into smaller skid-mounted subunits for ships with restricted deck space or power budgets, making phased retrofits viable on more constrained vessels. Tank insulation and cryogenic management were optimized through multi-layer insulation and active boil off control, preventing evaporative losses even in warm climates. Heat recovery from economizers and jacket water circuits reduces auxiliary boiler load and helps offset the roughly 35 percent thermal energy requirement for desorption. These design refinements mean CCS can be integrated without disrupting propulsion efficiency or voyage economics.
Scaling CCS Across Fleets
Early adopters, across emissions reduction technologies, are targeting their most carbon-intensive ships first, typically large tankers, bulk carriers, and gas carriers, to achieve the greatest reductions in both emissions and carbon cost exposure. These vessel types offer more deck space and higher power availability, making the integration of absorber towers, cryogenic tanks, and liquefaction systems for CCS simpler and less intrusive on cargo operations. The sectional nature of Wärtsilä’s system allows subsequent installations to benefit from shorter lead times and economies of scale, as major components can be prefabricated and tested ashore before delivery.
Fleet strategies are evolving toward averaging, where operators balance CCS-equipped vessels with non-equipped ships to achieve portfolio-wide emissions targets. Rather than retrofitting every ship, some owners are prioritizing 10 to 20 percent of their fleets for CCS, typically those with the longest trading ranges or the highest fuel consumption, and using the emissions reductions from those vessels to bring down their entire fleet’s carbon intensity. Wärtsilä’s modeling indicates that for many owners, fitting CCS to just a small share of their fleets can offset enough EU ETS liability to keep overall operating costs steady through the 2030s. This approach is especially viable for operators with mixed fleets, as the CCS-equipped vessels can shoulder more of the compliance burden while the remainder of the fleet transitions to low-carbon fuels at a pace that suits operational and market realities.
Modular construction and Wärtsilä’s global support network also help minimize disruption and off-hire. Most retrofits would not require extended drydocking but could be done alongside. Because the systems are built in skid-mounted sections, with pre-planning, owners can add or expand capture capability as regulations tighten, making it easier to manage capital expenditure and adapt to evolving carbon pricing regimes. Wärtsilä’s Sustainable Fuels analysis projects that, as methanol and ammonia take time to scale, deploying CCS fleet wide could cut over 70 percent of carbon output across a mixed fleet when combined with fuel efficiency upgrades and pooling strategies. For many owners, this means CCS will act as the backbone of compliance in the 2030s, with low-carbon fuels gradually assuming a larger share of the mix by 2040. Comparative modeling also shows that over a 10-year horizon, CCS retrofits can deliver lower-cost-per-tonne compliance rather than relying solely on low-carbon fuels, particularly given the high production costs and limited availability of methanol and ammonia in the current decade.
Carbon capture facilitates the energy transition.
A Bridge to Future Fuels
Carbon capture is not a competitor to low- and zero-carbon fuels; it is a bridge that enables their broader use while extending the life of conventional options. Projections from Wärtsilä’s 2024 transition modeling show that even with rapid growth in green methanol, ammonia, and hydrogen-based fuels, sustainable options may only cover one-third of shipping’s energy demand by 2035. This gap would leave many operators exposed to compliance penalties and high carbon costs if bridging technologies were not deployed in parallel.
By incorporating CCS, shipowners can continue to operate vessels using heavy fuel oil, LNG, or methanol while meeting tightening emissions limits and avoiding escalating costs under frameworks such as the EU ETS. These systems do not lock operators into any one fuel pathway, as the capture process is fuel agnostic, working effectively across conventional and low-carbon fuels alike. This flexibility helps owners protect the value of existing assets while positioning them to integrate alternative fuels when prices and supply chains mature.
As production of e-methanol and synthetic diesel scales up, in the future, captured CO2 could be supplied back to fuel producers as feedstock, closing the carbon loop and enabling owners to participate directly in the circular economy. This approach extends the utility of CCS hardware beyond the fossil fuel era, letting shipowners spread the capital investment across multiple fuel transitions. For many operators, this dual role—providing compliance today and supporting the emergence of synthetic fuels tomorrow—makes CCS a cost-effective and strategic choice. Wärtsilä’s projections indicate that although green methanol could begin closing the price gap with fossil fuels in the late 2030s, and ammonia may become competitive in the 2040s, CCS enables fleets to bridge that gap without incurring untenable penalties or scrapping viable ships prematurely.
Wärtsilä’s involvement in the Clipper Eris project demonstrates that full-scale carbon capture at sea is no longer an experiment or a proof of concept; it is a functioning, commercially deployed system capable of capturing the majority of onboard CO2 emissions. With capture rates consistently above 70 percent, integration alongside existing exhaust treatment, and a design tailored to the space, power, and operational constraints of oceangoing ships, the technology provides owners with a tangible solution to today’s regulatory and economic pressures.
Its significance lies in its ability to help shipowners avoid being cornered by unpredictable developments in the decarbonization landscape. Alternative fuels, while important, remain scarce and expensive, with infrastructure years away from matching global demand. Regulatory frameworks, from the EU ETS to the International Maritime Organization’s Carbon Intensity Indicator and potential market-based measures, will continue to evolve, and carbon prices are expected to rise sharply through the 2030s. By adopting CCS now, owners can keep fleets compliant while continuing to run proven fuels, avoiding costly scrapping or premature investment in unproven alternatives.
CCS also helps safeguard the value of vessels by enabling them to remain in service longer, even as fuel supply and regulatory conditions shift. This future-proofing is amplified by the system’s modularity and fuel-agnostic design, which keeps capture units relevant as fleets transition from fossil fuels to methanol, biofuels, or e-fuels. By supplying captured CO2 as feedstock for synthetic fuel production, operators can also integrate into the future fuel economy, creating an additional revenue stream and further offsetting the cost of adoption. For Wärtsilä, this technology represents more than a hardware offering. It positions the company as a partner to shipowners navigating the complex transition, providing not only systems but also life cycle support, operational data, and decarbonization modeling. As more vessels come online with CCS, costs will fall and performance will improve, benefiting the wider industry.
For shipowners, early adoption can deliver direct cost savings through avoided carbon penalties, competitive advantage in emissions-conscious charter markets, and resilience against future regulatory shifts. As part of a layered decarbonization strategy that includes alternative fuels, energy efficiency upgrades, and evolving operational practices, Wärtsilä’s onboard carbon capture stands as one of the few technologies capable of delivering immediate, material reductions in greenhouse gas emissions while keeping fleets commercially viable. It is not the end state for shipping, but it is a critical bridge to get there; a tool that enables the industry to move forward decisively while the long-term fuel transition takes shape.
Sigurd Jenssen is the director of exhaust treatment at Wärtsilä Marine.
Moving Vessel Profiler for Science
MVP300 sea trial on the Ifremer vessel Thalassa for Laboratoire de Météorologie Dynamique August 2025, off Nice, France.
By Georgia Haydock
Scientific decisions are only as good as the data on which they are based. In the face of growing demand for reliable, high-resolution and cost-effective ocean data, scientists are under pressure to do more with less.
A technology designed to fill this gap is AML Oceanographic’s Moving Vessel Profiler (MVP), an automated, real-time underway profiling system. Backed by more than 25 years of expertise, thousands of successful missions, and millions of individual casts, the MVP is a proven tool for optimized, cutting-edge ocean data collection. Long relied upon for hydrographic survey work, the MVP is now being embraced by leading scientific teams as a game changer for ocean science applications.
Compromising on data density, reliability or operational efficiency should not be an option. Whether it’s monitoring coastal systems, investigating climate-driven shifts, or tracking water quality after extreme events, the unique vertical profiling technology of the MVP is a highly strategic choice.
Why MVP for Science?
The MVP was designed for high-density water column profiles collected continuously and in real time, making it ideal for scientific applications. Data density isn’t just a luxury; it’s a requirement for accuracy and confidence. Gaps or inconsistencies in data force scientists to interpolate or make assumptions, thus introducing uncertainty and error. The MVP transforms water column sampling from a handful of sporadic casts to hundreds or even thousands of high-resolution profiles without interrupting operations. With the MVP, you get more data per kilometer of ocean covered, contributing to a more comprehensive understanding of the water column. For projects tracking subtle environmental changes such as nutrient gradients or turbidity plumes, this level of detail is critical to understand the behavior and implications of such features.
Ocean conditions change quickly. With real-time data collection, scientists are able to detect dynamic and localized phenomena as they occur and modify sampling routines on the fly. For example, after detecting a high-interest area such as a turbidity spike, you can re-route immediately to sample in greater detail. If you identify a low-variability area, you can shift focus to a zone with more scientific value. Decisions can be made without waiting for post-mission analysis, transforming research strategies from reactive to proactive. In turn, scientists are able to avoid wasting resources on low-impact areas and avoid redundant coverage.
The MVP is designed for continuous profiling. Whereas traditional CTD casts require stopping the vessel for every profile, the MVP deploys and recovers the tow body to its towed position while underway, eliminating the need for human intervention. This is a major efficiency gain: hundreds of profiles may be taken in the time it would normally take to get a handful.
A powerful tool when used in isolation, the MVP can also augment existing processes. Take a rosette sampler, for instance. With a deepwater MVP, a crew may be able to take fewer rosette samples, which typically use 2 to 5 hr. of static ship time, and complement the data with underway profiles to capture what’s happening between these casts. The two tools in tandem can improve operational efficiency and enhance data collection.
By improving both the quality and quantity of data collected per hour, mission ROI increases, and ship time—one of the most expensive resources in marine research—is maximized.
Third-Party Sensor Integration
The MVP is a highly versatile platform, designed to integrate the full suite of AML Oceanographic’s X2change field-swappable sensor heads, as well as most third-party instrumentation available to end-users.
The MVP is available in several formats: from smaller and all-electric to larger electrohydraulic platforms. Various sizes of tow bodies provide the ability to deploy not only the core hydrographic instrumentation (sound velocity, pressure, conductivity, and temperature), but also a wide array of oceanographic and scientific instruments. Currently, more than 15 different third-party sensors have been successfully integrated onto MVP tow bodies to support scientific missions, such as the Sea-Bird Scientific ECO Triplet and the SBE 18 pH sensor. Many customers request to configure the Rinko III dissolved oxygen sensor by JFE Advantech, the ECO FLNTU Instrument by Sea-Bird Scientific, and the SBE 49 FastCAT CTD by Sea-Bird Scientific.
AML’s MVPX2 instrument was designed to accommodate expansion ports, allowing the smaller tow bodies to support up to six parameters (X2change or other). The larger tow body design also incorporates a data telemetry module (DTM), offering a number of additional ports (bulkheads) that allow for both analog and serial instrumentation. With each instrument measuring up to four parameters, scientists could measure 10 to 12 parameters in the water column continuously while underway. The DTM also incorporates a power line mode and multiplexing, feeding these sensor outputs into one streamlined signal that sends instrumentation data from the tow body to the lab.
For all MVP operations, the systems require a pressure sensor for tow body depth. Outside of this, any restrictions come down simply to packaging: the instrumentation or sensor must physically fit into the tow body mechanically. Our dedicated team is ready and willing to find creative solutions to the configuration demands of your mission.
MVP30-350 with AML CTD and Turner Designs Cyclops-7F chlorophyll fluorometer gets installed on the RV Meteor No-
vember 2019, off São Vicente, Cape Verde. Supporting GEOMAR’s Modular Observation Solutions for Earth Systems (MOSES) project, the data will be used to aid understanding of the ocean carbon uptake in upwelling areas.
Case Studies
A small MVP was deployed recently as part of NASA’s Sub-Mesoscale Ocean Dynamics Experiment (S-MODE), a study of the small-scale weather patterns of the ocean: “The MVP30-350 worked great on our final S-MODE cruise, and we are pleased with the quality of the data,” said Tom Farrar, principal investigator of the NASA project and a senior scientist at the Woods Hole Oceanographic Institution. “The automatic profiling saved us a lot of the labor effort compared to a system we have that requires manual operation of the winch.”
In other recent work, a large MVP is in use by the Laboratoire de Météorologie Dynamique for an upcoming research project. This MVP will deploy a number of third-party environmental sensors, including but not limited to the Rinko III dissolved oxygen sensor, SBE 18 pH sensor and the Sea-Bird Scientific SUNA V2 nitrate sensor. “The ocean is full of dynamic structures just a few kilometers across that can change within days, yet they have an outsized influence on our climate, marine life, and the exchange of heat and carbon with the atmosphere,” said Sabrina Speich, a professor of physical oceanography and climate sciences at Laboratoire de Météorologie Dynamique. “Until now, these small-scale processes have been extremely difficult to observe in three dimensions and in real time. The MVP300 is a game changer. It allows us to profile the ocean down to the abyss while the ship is underway, capturing physical, chemical and biological data at unprecedented resolution. With it, we can finally map how these fleeting features work and better understand their role in shaping the climate system.”
Conclusion
As a platform for real-time, underway profiling, the MVP is far more than just a hydrographic survey tool: it’s now redefining what’s possible for ocean science. Fully compatible with both AML and third-party sensors, it provides the flexibility to build the data package your research mission demands. From climate research to coastal monitoring, the MVP helps you collect more data, waste less resources and act faster.
Connect with our team today to learn more about making your scientific mission more efficient at: sales@amloceanographic.com.
Georgia Haydock is the content strategist at AML Oceanographic.
Optical Sensors for Ocean Alkalinity Enhancement Research Pilot
Sequoia and Planetary personnel deploying the sensor-equipped mooring in the mixing zone for monitoring the OAE trial in Halifax, Nova Scotia, Canada. (Credit: Darren Calabrese, Carbon to Sea)
By Kirby Simon • Dr. Dariia Atamanchuk • Dr. Will Burt
Relying purely on emissions reductions is no longer sufficient to limit global warming to 1.5 or 2° C. To meet the annual global carbon dioxide (CO2) emissions targets set by the Intergovernmental Panel on Climate Change, CO2 removal strategies must be explored in parallel to reduce atmospheric concentrations of greenhouse gases. The ocean is a key player in many of these strategies as it naturally absorbs CO2 and sequesters stable carbon in the deep ocean for a long time. Marine carbon dioxide removal (mCDR) has therefore emerged as a critical tool in the fight against climate change.
Mineral-based ocean alkalinity enhancement (OAE) is a promising mCDR technique that enhances natural oceanic processes where alkaline materials dissolve over time and react with CO2 and water (H2O) to form stable bicarbonate. The addition of alkaline materials, such as olivine or magnesium hydroxide, to seawater (“dosing”) promotes this natural reaction, and as more dissolved CO2 is neutralized into stable carbon, more CO2 from the air can dissolve into the ocean. This acceleration of a natural ocean carbon cycle has a co-benefit of mitigating ocean acidification associated with CO2 uptake, with the added alkaline material increasing the buffer capacity of the seawater. These aspects of OAE, along with the favorable economic assessment, make it one of the more promising mCDR techniques, as evidenced by the rapid advancement in research and prevalence of field trials in recent years.
Through increased research efforts in the laboratory, in mesocosms, and in the field, significant progress has been made to demonstrate safety and viability for OAE. As research continues to transition toward more field trials and small-scale pilot projects, remaining knowledge gaps related to the safety and efficacy of these techniques become increasingly important to address.
Why Monitor Particles?
Key ongoing OAE research involves the fate of alkaline material added to the water, as well as potential environmental impacts associated with dosing. Particles play a critical role here; whether it is particles added directly to the water or interactions between the alkaline material and particles already in the water, particle properties govern many interactions that impact the efficacy and safety of OAE.
In the case of mineral-based OAE, the size, shape, and concentration of the minerals are important parameters that govern material dissolution rates and transport in situ. Interactions between particles, as well as processes at particle surfaces, can lead to particle aggregation and seabed deposition or secondary mineral precipitation, either of which can reduce the potential CO2 uptake of an OAE intervention. Additionally, these potential secondary effects can result in the generation of new particles and aggregates that should be monitored for environmental impacts.
Complex ocean modeling coupled with laboratory and mesocosm experiments have been used to study these scenarios to predict and assess alkaline material fate. As these research efforts grow and OAE deployments move out of the lab to the field, it is increasingly important to validate the results of these studies with in-situ measurements and sampling in real-world conditions.
Collecting these real-world measurements is not trivial, however. On top of the costs and complications of typical field work, OAE research has added complexities related to environmental permitting, public perception, and other considerations that make it difficult for any one entity to take on. This limits the number of opportunities to test OAE in the field and the scope of such research endeavors. Open science questions, such as those related to in-situ particle dynamics, are therefore difficult to answer without broader cross-sector collaboration and novel mechanisms to support research investigations.
Planetary Technologies of Dartmouth, Canada, a company at the forefront of OAE research and deployment, and the ocean researchers at Dalhousie University in Halifax, Canada, have partnered to conduct several OAE field trials in Halifax Harbor, Nova Scotia. Since 2023, alkaline materials (fine-grained magnesium hydroxide and magnesium oxide) have been added to an existing permitted powerplant outflow by Planetary, with the intervention heavily monitored by sensors and through discrete sampling at the dosing site and throughout the harbor.
As research progressed and alkalinity dosing ramped up, the desire to expand this collaboration grew. In the summer of 2024, the Carbon to Sea Initiative and the Centre for Ocean Ventures & Entrepreneurship, or COVE, in Dartmouth, Canada, announced a Joint Learning Opportunity (JLO) that invited new teams to participate in the field trial. The goal of the JLO was to provide access to the field trial and resources for deploying new technologies, engaging with local communities, and exploring complementary research to maximize the trial outcomes. Given both its importance and complexity, in-situ particle dynamics was listed as a JLO strategic research priority.
Sequoia Scientific Inc. of Bellevue, Washington, a leading manufacturer of submersible optical sensors for in-situ particle size and optical property analysis, saw the JLO as a perfect opportunity to use its sensors to contribute to fundamental particle research in OAE. Sequoia was selected as one of the four JLO project leads, and from the fall of 2024 through the spring of 2025 Sequoia worked closely with Planetary and Dalhousie-based researchers from the Ocean Alk-Align project (https://alkalign.ocean.dal.ca) to use the company’s sensors for laboratory experiments and in-situ monitoring to study alkalinity feedstock dissolution, transport, and accumulation.
Sequoia’s LISST-200X submersible particle size analyzer profiled throughout Halifax Harbor to monitor particle size and concentration.
Optical Sensors for Monitoring
Sequoia’s LISST (laser in-situ scattering and transmissometery) instruments were uniquely suited to support particle investigations in the OAE field trial. The LISST-Portable|XR, LISST-200X, and LISST-RTSSV (real-time size and settling velocity) were used in the laboratory to characterize Planetary’s alkaline material feedstock. These laboratory measurements were critical to interpreting field measurements with the contributed sensors: for example, measuring the particle size distribution (PSD) of the alkaline feedstock provided a particle “fingerprint” to look for in the in-situ data to distinguish between signatures of the alkaline material and other particles (e.g., sediment, plankton) or bubbles in the water that similarly scattered light. Experiments using a recirculating sample chamber could also be used to validate modeled alkalinity dissolution rates or study secondary precipitation mechanisms by measuring changes in the PSD (shape and magnitude) over time as particles recirculate and dissolve.
For in-situ measurements, Sequoia worked with Planetary to mount its LISST-Tau and LISST-OST (optical sediment trap) to a mooring at the dosing site in the mixing zone for near-continuous measurements of optical transmission in the water. These sensors were deployed from September 2024 to January 2025, performing measurements every 5 min., after which they were exchanged for a LISST-200X particle size analyzer through the end of the JLO in March. The LISST-200X measured mean particle size, PSD and concentration every 15 min. The high-frequency measurements from these sensors supported investigations into how quickly the particle environment changed when dosing was active versus paused, as well as how the alkalinity diluted and dissolved after addition to the turbulent water.
Additionally, a LISST-200X was deployed by Dalhousie researchers while performing approximately biweekly boat surveys for environmental monitoring. They hand-profiled the sensor at discrete locations in and around the mixing zone, as well as at several fixed sites throughout Halifax Harbor, to get depth-correlated particle measurements. These deployments aimed to study and constrain the spatiotemporal dynamics of alkalinity fate and transport.
Data Insights
Analysis of the data sets is ongoing; however, preliminary interpretations have provided meaningful insights into the in-situ particle environment. For example, when dosing was active, the optical transmission measured by the LISST-Tau and LISST-OST was lower in magnitude with a higher variance than times when dosing was inactive. When alkalinity dosing was paused, the measured transmission generally increased back to the approximate pre-dosing value quickly (on the order of tens of minutes). The trend implies a similarly short residence time of the alkalinity in the mixing zone, although this time is influenced by alkalinity dissolution, transport mechanisms (e.g., sinking or currents), and other environmental variables, making it difficult to quantify without additional sensor measurements and physical sampling to deconvolve these effects.
Laboratory measurements of the alkaline feedstock (a) enable the interpretation of in-situ PSD measurements (b) to monitor alkalinity fate.
Measurements from the mooring-mounted LISST-200X indicated a similar trend with dosing state. Median PSDs binned over a >40-hr. period of active dosing showed an elevated concentration of particles in the alkalinity “fingerprint” region compared to measurements from a similar period when dosing was paused. Importantly, these measurements demonstrated that the dosed alkalinity could be detected in situ in realistic dosing scenarios, which is a critical step toward directly monitoring alkalinity and observing its fate (e.g., dissolution, sinking, aggregation) in the near-field through optical measurements.
In contrast, there did not appear to be clear signatures of the alkaline material in the PSDs measured while profiling across Halifax Harbor further away from the dosing site. This may suggest rapid dissolution of the alkaline feedstock; more analysis is needed (e.g., correlation with other sensor data and physical samples) to support this theory. Across time, space, and depth, natural variability of the in-situ measured PSDs made it difficult to discern and assign any signatures to the alkaline material independent of whether dosing was active or paused. This result emphasized the importance of establishing an environmental baseline for each location such that natural versus alkalinity-induced perturbations can be identified in the measurements.
Outcomes and Roadmap for Research
The use of Sequoia’s optical sensors in the Halifax Harbor field trial demonstrates a critical step toward closing knowledge gaps surrounding particles in OAE research. The preliminary results highlight the importance of feedstock characterization for interpreting in-situ measurements as it relates to both detecting (e.g., identifying the alkalinity “fingerprint” in the PSD) and monitoring (e.g., measuring spatiotemporal changes in the PSD magnitude and shape) alkalinity in the environment. The particle measurements provide evidence that alkalinity can be detected in situ in real-world environments and dosing conditions, which is a critical first step to monitoring and parameterizing the dissolution and accumulation of the feedstock in the field to validate laboratory experiments and models.
With the collected data sets now published to the open-access Ocean Carbon and Acidification Data System (OCADS) hosted by NOAA, additional analysis and interpretation is possible by the broader scientific community. This data transparency is critical to maximizing the impact that these observations have on answering open questions in OAE research. As interest in OAE continues to accelerate and more work moves from the lab to the field, it is paramount to continue addressing knowledge gaps through collaborative, transparent, rigorous, and technologically advanced research investigations.
Sequoia and Planetary personnel mounting sensors to the mooring for OAE monitoring. (Credit: Darren Calabrese, Carbon to Sea)
Acknowledgments
The authors thank the Carbon to Sea Initiative and COVE for providing funding for the collaborative deployment of Sequoia’s sensors under the JLO. Additionally, the authors thank the teams at Dalhousie University, particularly CERC.OCEAN laboratory at the Department of Oceanography, and Planetary Technologies for supporting sensor integration, deployment, and maintenance throughout the field trial.
References
For a full list of references, contact Kirby Simon at: kirby.simon@sequoiasci.com.
Kirby Simon is the science and technology lead at Sequoia Scientific Inc.
Dr. Will Burt is the vice president of science and product at Planetary Tech.
Marine Software Developer to Scale AI-Driven Fuel Saving Platform
Swedish AI company Cetasol has raised $2.7m in a seed-funding round to scale its AI-driven decision support and digital twin technology to reduce fuel use for ships.
The investment was co-led by BackingMinds and Shift4Good, with ongoing support from existing investor Sarsia.
Cetasol’s primary product, iHelm, is designed to collect data from vessels and uses the company’s digital twin technology for both vessel and engine.
The system processes information through edge computing and provides the captain with real-time recommendations for fuel savings.
The operational data is then transmitted to a cloud-based dashboard. This allows users to access real-time and historical performance metrics, address maintenance needs proactively, and track compliance requirements, stated the company.
BackingMinds CFO and Investment Director Niclas Wijkstrom said: “Cetasol is tackling one of the maritime industry’s biggest blind spots. While most solutions target the largest vessels, nearly 90% of the global fleet consists of small- and medium-sized ships that are underserved and often lack access to affordable optimization tools.”
According to Cetasol, most innovation and investment have targeted electrification and large vessels. Small and mid-sized vessels represent nearly 90% of the global fleet and present an opportunity for rapid and scalable reductions in emissions, noted the company.
The iHelm AI platform is designed to optimize fuel consumption and operational performance for these vessels, with estimated fuel savings ranging from 10% to 25%.
Cetasol CEO and Founder Ethan Faghani said: “This investment confirms that our approach to AI-driven decision support and maritime sustainability is both needed and trusted. With this support, we are scaling faster and wider — delivering intelligent solutions to maritime operations globally.”
Following this investment, Cetasol intends to increase its commercial reach in the maritime industry by expanding its presence in key markets and extending partnerships.
The company plans further development of its technology platform as it seeks broader implementation of AI-based decision support for the optimization of energy use and emissions reduction.
Cetasol also aims to provide solutions that respond to industry requirements for data-driven operations and sustainability measures.
High-Resolution Sub-Bottom Survey Reveals Hidden Histories in Sicily
Sub-bottom profile acquired in Porto Empedocle, revealing the local seabed stratigraphy. The data have been processed with gain offset, amplitude envelope, seabed detection and water column extraction to enhance reflector clarity. Inset: zoomed view of the section containing the acoustic anomaly, showing its distinct geometry and strong reflectivity relative to surrounding stratification.
By Alfonso R. Analfino • Giuseppe Decaro • Francisco J. Gutiérrez
The coastal and seabed environments surrounding Sicily are layered with geological complexity and millennia of human history. In a recent high-resolution sub-bottom profiling survey conducted in Porto Empedocle harbor, high-resolution acoustic data were acquired that reflect this dual legacy. The work was part of a project encompassing underwater archaeological surveys for archaeological risk assessment in preparation for the creation of a route for a submarine pipeline near Porto Empedocle.
Using a GeoAcoustics GeoPulse Compact sub-bottom profiler paired with a Trimble Applanix POS MV WaveMaster inertial navigation system, the team mapped the stratigraphy of the harbor seabed with high resolution. The data set revealed soft silt deposits draped over Pliocene-aged gray clay from the Monte Narbonne Formation. A strong acoustic return at approximately 22-m depth—anomalous in character and potentially anthropogenic—was of particular interest.
This article outlines the tools and methodology employed, the workflows developed for data acquisition and processing, and a representative example from the data set. The Porto Empedocle survey demonstrates how modern remote sensing technologies, when applied with geological and historical awareness, can support both environmental monitoring and the safeguarding of submerged cultural heritage.
Tools and Methodology
Survey operations were conducted aboard Neptune 1, a 6.5-m workboat configured for high-resolution geophysical investigations. The primary system used was the GeoPulse Compact sub-bottom profiler, chosen for its ability to resolve fine sedimentary layering in shallow marine environments. Positioning and motion compensation were provided by a POS MV WaveMaster system, integrating RTK-GNSS, gyrocompass, and MRU sensors for centimeter-level accuracy. Data acquisition was managed using QPS Qinsy version 9.6.2 and Geo Marine Survey Systems GeoSuite Acquisition, with post-processing performed in GeoSuite AllWorks. Additional tools—including AutoCAD Map 3D, Blue Marble Geographics Global Mapper, and Golden Software Surfer—supported mapping and spatial data handling. Power on board was supplied by a portable Honda EU22i inverter generator.
Survey methodology followed best practices for harbor sub-bottom profiling. Survey lines were planned to ensure full coverage of the proposed pipeline corridor. Acquisition parameters were adjusted in real time to match seabed conditions. Prior to acquisition, all systems were calibrated and time-synchronized to guarantee alignment between acoustic, motion, and positioning data.
Setup, Deployment and Configuration
Mobilization took place over two days in June 2025. On June 10, the vessel was launched, and all instrumentation was installed, tested, and calibrated. Data acquisition began the following day and was completed within the same operational window.
Neptune 1 was selected for its compact size and maneuverability, enabling precise navigation within the harbor and along the planned corridor. All survey systems—including the POS MV, GeoPulse Compact, and antennas—were installed on a rigid pole, deployed over the side of the boat to minimize mechanical offsets and reduce motion artifacts.
The POS MV WaveMaster was configured with dual GPS antennas (2-m separation) to ensure heading accuracy, and its IMU was aligned relative to the vessel’s center of gravity and transducer. Offsets were configured in POSView and Qinsy software to maintain consistency across coordinate systems and enable real-time compensation of roll, pitch, heave, and yaw.
The GeoPulse Compact was pole-mounted and submerged to a consistent draft of 0.5 m. Pre-survey trials were conducted to optimize source power, gain and firing rate based on local sediment properties. Survey lines were spaced at 5-m intervals and oriented parallel to the shoreline, as requested by archaeological oversight, ensuring high lateral resolution and full coverage.
Deployment of the Neptune 1 survey vessel in Porto Empedocle, configured for high-resolution sub-bottom profiling. At right, from top to bottom: acquisition interfaces from Qinsy and GeoSuite Acquisition; the Trimble Applanix POS MV system used for positioning and motion compensation; and the GeoAcoustics GeoPulse Compact sub-bottom profiler used during the survey.
Pre- and Post-Survey Accuracy Checks
Accuracy validation was integral to both mobilization and demobilization. The POS MV, equipped with a GPS azimuth measurement system (GAMS), provided stable and accurate position and attitude data throughout. GAMS was particularly critical in the nearshore environment, where wave-induced heave can degrade sub-bottom data quality. Real-time heave compensation significantly enhanced signal clarity and interpretability.
Before acquisition, figure-eight maneuvers were performed to calibrate heading and verify antenna alignment. During the survey, continuous monitoring ensured roll, pitch, yaw and heave remained within operational thresholds. Post-survey analysis of navigation and motion logs confirmed consistent accuracy, with no drift or latency. The process delivered subdecimeter horizontal and vertical accuracy, meeting the resolution requirements for archaeological assessment.
Operating in a low-noise environment is essential for high-resolution profiling. The EU22i portable generator provided clean, true-sine wave power with minimal electromagnetic interference. During quiet periods (0 percent transmit volume), the GeoSuite Acquisition software’s power spectral density display enabled noise baseline assessment and confirmed system installation quality. This ensured the profiler operated at peak sensitivity, maximizing data quality and interpretability.
Online Data Optimization
During acquisition, optimal system configuration was achieved through iterative testing informed by prior knowledge of the local environment and real-time data quality monitoring. The GeoPulse Compact sub-bottom profiler was configured in chirp mode, operating across a 1- to 18-kHz frequency range. This setup offered excellent vertical resolution, enabling clear identification of sedimentary structures while maintaining good penetration—essential for interpreting buried features in shallow marine environments.
Real-time visualization in GeoSuite Acquisition allowed the team to assess signal strength, noise levels and seabed response. Parameters such as waveform type, volume output, and ping interval were fine-tuned accordingly. The software’s ability to display power spectral density during “listening” periods proved especially useful for identifying environmental or onboard noise sources. This online optimization process ensured a high signal-to-noise ratio and data fidelity throughout the survey.
Data Processing Workflow
Post-survey, sub-bottom profiler data were processed using GeoSuite AllWorks, an integrated software platform designed for high-resolution, single-channel seismic analysis. Initial quality control included seabed tracking, envelope scaling, and filtering to remove low-frequency noise (e.g., 50-Hz interference) and frequencies beyond the system’s 18-kHz range. An amplitude envelope and automatic gain control were also applied to enhance reflector visibility.
GeoSuite’s real-time layback correction feature ensured precise positioning of the seismic source and receiver relative to the GPS antenna, compensating for dynamic offsets. The dual-channel acquisition capabilities, though not exploited in this survey, are designed to improve horizontal resolution or reduce noise when using multiple sources. Additional spatial and projection data were managed through the software’s built-in coordinate reference system library and compatibility with external cartographic layers (e.g., bathymetry, satellite overlays). These tools allowed for effective visualization, navigation verification, and eventual integration of processed lines with geological interpretations.
The Geology
The harbor of Porto Empedocle is located along the southern coast of Sicily, within a geologically complex area influenced by its position at the southern edge of the Hyblaean Plateau and near the Gela-Caltanissetta Foredeep Zone. This transitional setting between the Apenninic-Maghrebian orogenic belt to the north and the African Continental Shelf to the south has given rise to a diverse and tectonically active stratigraphy. The region is marked by compressional and extensional structures, with a prominent northwest-southeast fault separating units with distinct depositional histories.
The stratigraphy observed in the area reflects alternating marine, transitional and continental depositional environments. At depth, the sedimentary sequence includes Pre-Miocene basement units, such as Mesozoic limestone forming the substrate of the Hyblaean carbonate platform. These are overlain by Lower to Middle Miocene globigerina marks and limestone (Ragusa and Tellaro Formations), deposited in a medium- to deepwater marine setting during the early phases of the Miocene transgression.
Late Miocene sequences, particularly those associated with the Messinian Salinity Crisis, are represented by the Gessoso-Solfifera Formation—composed of laminated and saccharoidal gypsum with interbedded clay and calcarenite. These layers are often identifiable in seismic profiles as strong, continuous reflectors.
The Pliocene is marked by pelagic gray and bluish clays (Trubi and Monte Narbonne Formations), which are rich in microfossils and serve as excellent stratigraphic markers. These units form much of the local coastal relief, including features such as the nearby Scala dei Turchi cliff. A gradual transition to more turbidite facies is also observed in this interval.
Shallower layers, from the Pleistocene to the Holocene, consist of bioclastic calcarenite (e.g., Marsala and Terranova Formations), as well as marine terraces, lagoonal silts, coastal sands, and recent alluvial deposits—reflecting glacial sea level cycles and deltaic-littoral processes.
Sub-bottom profiler data confirmed the presence of a well-layered surficial cover of soft silts and sands, typically 1- to 10-m thick, resting atop a more rigid substrate of Pliocene clay or calcarenite. Internal reflectors often appear horizontal or gently undulating, in some cases suggesting erosional paleo-surfaces or submerged paleo-channels formed during lower sea levels in the Pleistocene.
An Anthropogenic Anomaly?
Among the notable features identified in the seismic profiles was a high-amplitude reflector at approximately 22 m below the seabed. Its geometry—marked by clear boundaries, localized convex shape and stratigraphic discontinuity—raises the possibility of anthropogenic origin.
In archaeological terms, the Agrigento Coast was part of ancient Akragas and has yielded numerous submerged artifacts, including Greek and Roman shipwrecks, amphorae, and port infrastructure. Given sea level rise since the Holocene, the anomaly’s depth suggests it may lie within a paleo-environment that has been submerged for more than 8,000 years.
Three plausible interpretations include: a buried shipwreck, possibly Greek or Roman, fully encased in sediment; some structural remains of a submerged port—such as a quay, breakwater, or foundation platform; or a pre-Holocene coastal settlement now buried beneath marine transgressive layers.
While these hypotheses are speculative, the anomaly exhibits acoustic signatures consistent with man-made objects, such as high reflectivity, acoustic shadowing and deviation from natural stratification. Full confirmation would require targeted archaeological investigation, including broader sub-bottom profiler coverage and, potentially, direct sampling or excavation.
Survey Challenges
Sub-bottom profiling in coastal and harbor settings presents numerous operational challenges, particularly when seeking both high resolution and sufficient penetration. The success of the Porto Empedocle survey relied on carefully managing these trade-offs.
A key challenge was optimizing frequency selection, with the chirp mode (1 to 18 kHz) offering the best compromise between vertical resolution and sediment penetration. Adjusting pulse length, gain settings (especially time-varying gain), and trigger intervals required field testing and active monitoring to maintain consistent quality across varying substrates.
Environmental conditions also posed limitations. Surface turbulence and propeller-induced vibrations can reduce signal clarity, particularly in soft or gas-rich sediments. Careful control of survey speed, transducer immersion depth and data windowing were essential in overcoming these effects.
Instrument synchronization and offset calibration were critical to maintaining spatial accuracy. The POS MV’s integration with GAMS helped mitigate heading and heave uncertainties, while software configuration ensured alignment between the transducer, IMU, and GNSS antennas. Acoustic interference from nearby systems or vessel electronics was minimized through frequency management and by using low-noise power from an inverter generator.
Altogether, the survey required constant adjustment and quality control, but with careful tuning and experienced operation, high-quality stratigraphic data were successfully obtained.
Conclusion
The high-resolution sub-bottom profiling survey conducted in the harbor of Porto Empedocle successfully met its dual objectives: mapping sedimentary stratigraphy in a geologically complex coastal environment and supporting archaeological risk assessment ahead of infrastructure development. The use of the GeoPulse Compact system, combined with precision positioning via the POS MV and real-time monitoring through GeoSuite software, enabled the collection of clean, high-fidelity seismic data despite the operational challenges of a shallow, dynamic marine setting.
The resulting imagery provided clear identification of stratified Holocene and Pleistocene deposits and confirmed the presence of underlying Pliocene clay from the Monte Narbonne Formation. These geological units not only align with regional stratigraphy but also revealed features such as paleo-surfaces and possible buried channels indicative of past sea level changes.
The detection of a strong, geometrically distinct reflector at approximately 22 m below the seabed raises the possibility of an anthropogenic structure, such as a buried wreck or submerged port element. Further investigation is needed to confirm its nature, and this finding underscores the value of sub-bottom profiling in coastal archaeological assessments.
The survey demonstrates how modern marine geophysical methods—when carefully configured, optimized in the field, and integrated with geological and archaeological context—can produce actionable insights for environmental monitoring, heritage protection, and engineering planning in sensitive nearshore areas.
References
For a full list of references, contact Alfonso Ricardo Analfino at alfonso@geonautics-srl.com, Giuseppe Decaro at g.decaro@geonautics-srl.com or Francisco J. Gutiérrez at francisco.gutierrez@geoacoustics.com.