The SS United States passes South Florida on its final voyage to become an artificial reef off the Florida Panhandle.

The exact location of where the SS United States will be sunk along the Gulf Coast fhas not been set, but it is expected to be about 20 nautical miles south of the Destin-Fort Walton Beach area.

The SS United States, built more than 70 years ago, is being towed from Philadelphia to Mobile, Alabama, to become the world's largest artificial reef.

The last voyage of the SS United States is now underway, once its prepped and cleaned it will sink and become the world’s largest artificial reef.

The SS United States sat in South Philadelphia for 30 years before finally leaving its dock after several setbacks and weather delays. Tug boats moved the ship from its pier into the river, where it waited for the changing tides to carry it further down the river, and into the Atlantic Ocean.

The SS United States approached the last leg of its East Coast transit Wednesday, before its tow turns to the west and its next destination of Mobile, Ala., where the historic liner will be prepared f

The SS United States is now off the coast of Florida. After a series of delays, the 990-foot ocean liner left Philadelphia last week, on its way to become the world's largest artificial reef off the Okaloosa County coast.