The United States Coast Guard operates on Martha's Vineyard out of Menemsha Station, where it has authority over the waters of the Vineyard Sound up to the Rhode Island state line, Buzzard's Bay, Block Island Sound, and the waters extending to 50 nautical miles south of the the Vineyard. It is primarily charged with search and rescue, law enforcement and Department of Homeland Security missions, as well as overseeing maritime safety and security.
