The Interagency Working Group on Ocean and Coastal Mapping announces progress report on mapping U.S. ocean, coastal, and Great Lakes waters

The federal Interagency Working Group on Ocean and Coastal Mapping (IWG-OCM) has released the fourth annual report on progress made in mapping U.S. ocean, coastal, and Great Lakes waters. Knowledge of the depth, shape, and composition of the seafloor has far-reaching benefits, including safer navigation, hazard mitigation for coastal resilience, preservation of marine habitats and heritage, and a deeper understanding of natural resources for sustainable ocean economies. The 2020 National Strategy for Mapping, Exploring, and Characterizing the United States Exclusive Economic Zone (NOMEC) and the Nippon Foundation-GEBCO Seabed 2030 Project make comprehensive ocean mapping a priority for the coming decade. The Unmapped U.S. Waters report tracks progress toward these important goals.

Pulling from an analysis of publicly available bathymetry, the report presents the percentage of unmapped U.S. waters by region and shows our progress towards filling these basic bathymetry data gaps with each passing year. At the end of 2022, 67,700 square nautical miles of new bathymetric data coverage were added since the last report.

Progress was made on a number of fronts. Roughly half of the total gains came from collaborative mapping projects funded by NOAA, USGS, and BOEM in the Atlantic’s Blake Plateau region and the Caribbean. Major gains in the Alaska-Arctic region stem from new bathymetric data added to NOAA’s National Centers for Environmental Information archives as a result of partner efforts to share existing data for Seascape Alaska, a new regional mapping campaign.

“This year’s report shows that we made significant progress toward the goal of fully mapping U.S. Waters in 2022. The area brought up to modern mapping standards last year is roughly the size of the state of Minnesota. However, we still have far to go. We will continue to push on all fronts, including building partnerships, encouraging people to share existing data, pursuing additional resources for new data acquisition, and innovating our mapping systems and workflows to accelerate progress toward NOMEC and Seabed 2030 goals.”

—Rear Adm. Benjamin Evans, director of NOAA’s Office of Coast Survey

Percent of U.S. waters that remain unmapped as of January 2023:

  • U.S. total – 50% of 3,590,500 square nautical miles (snm)
  • Atlantic and Gulf of Mexico – 37% of 472,200 snm
  • Great Lakes – 92% of 45,100 snm
  • Caribbean – 30% of 61,600 snm
  • Alaska – 66% of 1,080,200 snm
  • Pacific (California, Oregon, Washington) – 19% of 239,700 snm
  • Pacific Remote Islands and Hawaii – 47% of 1,691,700 snm
An image of the front page of the unmapped waters progress report.
Geographic distribution and extent of the unmapped areas within U.S. ocean, coastal, and Great Lakes waters. Analysis conducted in January 2023.

Multibeam and lidar surveys are the two primary sources of bathymetry needed to fill these gaps. In support of the integrated ocean and coastal mapping goal to “map once, use many times,” all of the data collected in this effort are publicly available to benefit numerous users. For the latest status on these efforts and how you can contribute, visit

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