Once a premier ocean liner sporting one of the world's most powerful engines, the SS United States is set to reach another historic benchmark later this year when it becomes the world's largest man-made reef. Harbored in Philadelphia's Delaware River since the 90s, the now-decaying ship made headlines last week when it set off for Mobile, Alabama, where it will embark on its final voyage: a planned sinking twenty miles off the Gulf Coast.

Built during the post-World War II engineering boom, the SS United States employed a world-class engine that made it the fastest trans-Atlantic oceanliner in history— still holding the speed record some 60 years later. In many ways, this propulsion system was the final hurrah of an era of luxury transoceanic travel made obsolete by the rapid growth of long-distance flights. Retired after just 16 years of operation, the once pinnacle of high-speed luxury travel sat idle in a shipyard for years. Now, one of the shipping industry's greatest technological marvels will delight visitors of a very different ilk. In a $10.1 million deal with the Okaloosa County, Florida, tourism board, the salvageable remains of the SS United States will be stored in a dedicated onshore museum, while the ship itself will sink 180 feet below the surface, becoming a hotbed for wildlife and diving tourists alike.