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Diver-Based Rapid Response Capability For Maritime Security Operations
New Technologies and Programs Enable Cost-Effective Training Of Military and Civilian Divers for Explosive Ordnance Disposal

Dennis Gallagher
Senior Project Engineer
Naval Surface Warfare Center Panama City Division
Panama City, Florida

Maritime security dive operations cross many geographic boundaries and regional jurisdictions. Performed routinely in dark or turbid water in near-zero visibility conditions, these operations include underwater searches of ship hulls, piers, docks and bottom berthing areas for contraband, mines and other threats.

In many locations throughout the country, divers remain the sole rapid response capability against waterborne threats. Developing technology and training that can decrease the time needed to search an underwater area, increase the probability that threats will be found and decrease risk to divers is essential. Technology and training that can be used by multiple agencies—both military and civilian—is critical.

The U.S. government's Combating Terrorism Technical Support Office oversees interagency programs that are developing technologies and solutions to address current and emerging maritime threats. Under its Maritime-Port Security Counterterrorism Initiative Program, the Naval Surface Warfare Center Panama City Division partnered with Florida State University Panama City and Sound Metrics Corp. (Lake Forest Park, Washington) to develop a diver-based rapid response capability for maritime security operations. This capability involves an acoustic-lens imaging sonar, an advanced military diver mask-mounted display system and a mission-specific portable training program that can be used by both military and civilian agencies.

Military diver display.

Waterborne Threats and Organizational Challenges
The U.S. domestic maritime domain includes ports, harbors, associated facilities and a vast network of inland waterways, canals, bridges and dams. With billions of dollars worth of commerce moving annually through this domain, the task of safeguarding the nation's ports and harbors is critical to economic stability and security. The complexity and changing conditions in the maritime domain produce a dynamic and hazardous emergency response environment. Because many naval installations are based in U.S. ports, this creates a unique set of military and civilian, or cross-sector, challenges.

U.S. Navy Explosive Ordnance Disposal (EOD) divers are presently the only personnel properly trained and qualified to deal with waterborne explosive devices from search, identification, classification and prosecution. However, domestic maritime security response is not their primary mission, and nearly 70 percent of Navy EOD forces are deployed outside the continental United States.

The United States Coast Guard is the federal-level organization most responsible for domestic maritime security response. While they do have some underwater hazardous device (UHD) search capability, their integrated capabilities for search, response, identification, classification and prosecution are limited. Throughout most of the country, public safety dive teams—typically police and firefighters—are the first response asset employed for maritime security dive operations. With a few notable exceptions, public safety dive teams lack the equipment and training necessary to provide an effective UHD response. To complicate things further, many public safety dive teams are created as a collateral duty responsibility, which means time dedicated to maritime security response must be done at the expense of other vital law enforcement or firefighting duties. The widely scattered distribution of trained military response personnel and a lack of adequately trained and equipped civilian responders create significant vulnerabilities. Addressing these necessitates an aggressive joint-service and interagency approach.

The Federal Bureau of Investigation's Hazardous Devices School, coordinating with the Department of Homeland Security and Department of Defense, has developed and implemented a national training process to equip public safety dive teams with the skills and procedures they need to operate more safely in the waterborne environment and to integrate with other bomb squad assets during a UHD event.

Developing Technologies for Diver-Based Response
ROVs, AUVs and site-specific sensors are adding significant security response, monitoring and situational awareness for the maritime domain. However, divers remain an essential component to maritime domain security capability as they are a widely distributed, highly flexible, indigenous and rapidly deployable response asset. They can be used to augment and enhance these other systems. Providing divers with tools that can help them search underwater areas more quickly while increasing their safety is essential.

Acoustic-Lens Imaging Sonar. The sonar system used is the Dual-frequency IDentification SONar Diver-Held (DIDSON-DH), manufactured by Sound Metrics. This multibeam sonar uses 96 individual sonar beams (0.3° bandwidth) at 15 frames per second focused through a set of acoustic lenses to produce high-resolution sonar imagery.

Confined water training.

The diver-held model allows single-hand underwater operation and has a rechargeable battery pack and a commercial mask-mounted visual display. The diver can adjust sonar range, zoom in and out on images, and record still pictures and video. The sonar shifts automatically between low-frequency (1.1 megahertz) and high-frequency (1.8 megahertz), and has a depth sensor, electronic compass and tilt sensor.

Twenty prototype DIDSON-DH systems have been tested by U.S. Air Force Combat Search and Rescue (CSAR) teams and are presently being used in their operations.

Advanced Military Diver Mask-Mounted Display. A visual display system is an essential means of providing high-data-content sensor information to a diver. Unfortunately, hand-held displays are nearly useless in an underwater environment characterized by high turbidity and zero visibility. A diver mask-mounted 'near-to-eye' display system incorporating microdisplay technology is a more efficient option for providing high-data-content images to divers. Designing such a display system, however, has several design challenges: combining the conflicting requirements of small physical size and weight, high strength for use at depth, large eye-relief for use with a dive mask and minimum power.

The Naval Surface Warfare Center Panama City Division has developed a number of diver mask-mounted display systems. The most recent system is a lightweight, binocular, mask-mounted display that provides color, 800-by-600-pixel-resolution imagery regardless of ambient visibility conditions. It incorporates organic LED micro displays that have been color-balanced and contrast-matched using custom-written U.S. Navy software.

The fixed-focus optical system uses multielement lenses that provide an extended 35-millimeter eye relief, allowing the system to be placed outside the dive mask without losing full display screen field-of-view. The optical lenses are assembled at a specific offset angle to allow rapid, binocular image convergence for approximately 95 percent of divers without the need for an interpupillary adjustment mechanism. These new systems are superior to earlier commercial versions; they have higher contrast, brighter color, smaller physical size, larger eye relief, lower cost and lower power consumption, allowing divers to clearly view high-data-content images in zero-visibility water conditions. The newest prototype is designed for operational use to a depth of 300 feet.

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Dennis Gallagher is a senior project engineer in the Naval Surface Warfare Center Panama City Division's Underwater Systems Development Branch, where he presently heads the Information-Data Display Systems and Technologies Group. He received his bachelor's degree in mechanical engineering from Florida Atlantic University in Boca Raton, Florida.

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