SS United States, Moored in Philadelphia for 30 Years, Sinks Off Florida to Become the World’s Largest Artificial Reef

The ocean liner SS United States, moored at the Philadelphia waterfront for nearly 30 years, sank off the Florida coast on Wednesday to become the world’s largest artificial reef.

The sinking began at about 1 p.m. Central time on Wednesday. Crews removed plugs from the hull to let seawater in, sinking the ship slowly without explosives. By evening the hull tilted onto its side and slipped beneath the waves.

The ship will rest on the floor of the Gulf of Mexico about 25 miles southwest of Destin, Florida. The plan is for it to sit upright at a depth of 180 feet, with the upper deck about 50 feet below the surface.

The ship is the largest passenger liner ever built in the United States and the fastest to cross the Atlantic. Launched in 1951, it crossed the Atlantic in under four days and carried four presidents and the Mona Lisa. It retired in 1969 as commercial air travel took off.

After retirement the ship sat moored in Philadelphia, facing the scrap heap. Okaloosa County, Florida, bought it for about $13 million and prepared it for disposal at sea at a shipyard in Mobile, Alabama.

The ship now anchors a collection of more than 500 artificial reefs built by Okaloosa County. Together with the aircraft carrier Oriskany, sunk off Pensacola in 2006 at 888 feet, the area will hold the first and second largest artificial reefs in the world.

The sinking was livestreamed, with dozens of tugboats and recreational vessels watching. It is expected to become a destination for divers and anglers.