On May 28, 2020, four uncrewed vessels departed Alameda, California, to begin their transit across the Pacific Ocean, through Unimak Pass, across the Bering Sea, and into the Arctic. These small, uncrewed vessels, powered only by wind and sun, arrived at Point Hope, Alaska, in early August to start an ambitious project acquiring new depth data along the 20- and 50-m depth contours from Point Hope to the Canadian border. This was the start of a challenging Arctic project that would contend with weather, sea ice and equipment failures, all while avoiding potential conflicts with indigenous subsistence hunting. 

With COVID-19 causing operational limitations for crewed vessels, Coast Survey leveraged uncrewed capabilities to continue surveying, in line with NOAA’s Uncrewed Systems (UxS) Strategy. Working through Coast Survey’s contract partner, TerraSond, Saildrone’s 23-ft. uncrewed sailing vessels were selected based on their operational capabilities and nearly silent operation. These vessels rely exclusively on wind power for propulsion, and solar energy to power electronics and sensors. For this project, the Saildrones were configured with a low-power single-beam echosounder (235 kHz), along with a suite of meteorological and oceanographic sensors. This configuration provided critical depth information for Coast Survey, while also providing a wealth of environmental data for NOAA and the greater scientific community.

In early September, while the Saildrones were surveying north of Utqiagvik, the project team learned subsistence hunting along the North Slope was starting. Coast Survey collaborated with the Alaska Eskimo Whaling Commission (AEWC) to develop an operational plan that mitigated conflicts with subsistence hunters while still achieving Coast Survey’s project objectives.

In early October, the Saildrones were acquiring additional bathymetry in Norton Sound before starting the 3,000 nautical mile journey back home to Alameda, California. 

Once the Saildrones safely reach Alameda, the data will be processed by TerraSond and delivered to NOAA. Following quality control processing, the acquired bathymetry will update nautical charts across the Arctic. All data acquired as part of the contract will be made publicly available, and are suitable for use in coastal modeling, weather forecasting and various other Arctic research projects.

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