Cleveland, OH – A major federal mapping effort is underway across the Great Lakes this week as the NOAA Ship Thomas Jefferson returns to service in the region for the first time since 2022, focusing on critical waters in Lake Erie and Lake Ontario.
According to NOAA, the vessel and its crew are surveying western and central Lake Erie and eastern Lake Ontario to improve navigation safety for commercial shipping, fishing operations, and recreational boating across Ohio, New York, and the broader Great Lakes region.
Western Lake Erie, one of the busiest and shallowest areas in the Great Lakes system, has not been fully surveyed since the 1940s. Officials say updated seafloor mapping is essential to identify hazards, reduce vessel collisions, and support safer transit across heavily traveled waterways near cities like Cleveland, Toledo, and Buffalo.
Additional work will take place within Lake Ontario National Marine Sanctuary to help identify and protect critical underwater habitats. NOAA navigation response teams will also conduct surveys this season in Thunder Bay, Michigan; Braddock Bay, New York; and Green Bay along the Michigan-Wisconsin border.
The effort is part of broader initiatives, including Lakebed 2030 and the Great Lakes Restoration Initiative, aimed at improving mapping coverage in what NOAA describes as the least-charted waters in the United States. Currently, only about 17% of the Great Lakes have been fully mapped.
This summer, operations will expand with the use of an uncrewed surface vehicle known as DriX near Oswego, New York, capable of operating for up to four days while collecting high-resolution sonar data.
Officials say the updated mapping will also support storm modeling, environmental protection, and maritime commerce across the region.
