The ship, which was once the fastest in the world and longer than the Titanic, was intentionally sunk off the coast of Florida, in order to create the world's largest artificial ocean reef.
The SS United States spent nearly 30 years docked in Philadelphia before it was moved to Florida, where it will become a home for sea life and an underwater attraction for marine enthusiasts.
Activists unsuccessfully fought for the historic liner - which crossed the Atlantic Ocean hundreds of times - to be preserved as a museum.