Crews removed plugs from the ship's hull, allowing it to fill with water without explosives. After hours of delays, the nearly 1,000-foot liner tilted onto its side and slipped beneath the waves in about five hours — a stark contrast to its record-setting 1952 maiden voyage, when it crossed the Atlantic in under four days to claim the Blue Riband.

Launched in 1951 and longer than the Titanic, the SS United States carried four U.S. presidents, the Mona Lisa and a long list of 20th-century movie stars. It had spent decades moored and deteriorating in Philadelphia before Okaloosa County purchased it for $1 million in 2024 from the SS United States Conservancy, which had served as its custodian.

The ship now rests just over 20 nautical miles from Destin's beaches, positioned so that its upper decks remain within recreational diving limits. Its hull was stripped of toxic materials and bulky components before the sinking, according to county tourism officials.

"For those of us who love shipwrecks and love ships in general, it was way more tragic to see it sitting and rusting away at the dock," said Karen Flynn, a wreck diver with the Maryland-based Atlantic Wreck Divers, whose club booked a charter boat within days of the sinking date being set. "We've dove everything that you can around the world. This will just be one more unique, new thing for us to dive."

Okaloosa County has sunk hundreds of artificial reefs, many of them ships or boats, but tourism director Jennifer Adams said this is by far the largest. Reefs currently generate roughly $10 million to $12 million in annual economic benefits for the county, she said, and she expects that figure to climb — enough, she predicted, for the county to recoup its $10 million investment within a couple of years.

The SS United States joins the USS Oriskany, an 888-foot post-war aircraft carrier sunk by the Navy off Pensacola in 2006, giving the Panhandle region claim to the first- and second-largest artificial reefs in the world. Adams said plans are already in the works to sink five or six more reefs.

Florida has created more than 4,000 artificial reefs since 1940, according to the state Fish and Wildlife Conservation Commission. A National Oceanic and Atmospheric Administration analysis of 2017 data found that visits to just a few of the state's artificial and natural reefs generated almost $1 billion in annual economic benefits.

Andrew Ropicki, an economist at the University of Florida, said Okaloosa and neighboring counties have achieved a "critical mass" of planned shipwrecks that lets them capture more tourism dollars than other areas. But he cautioned that overinvestment in reefing could eventually produce diminishing returns as visitor interests shift or divers are overwhelmed by choices.

For Susan Gibbs, the sinking is a complicated moment. She heads the SS United States Conservancy and is the granddaughter of William Francis Gibbs, the naval architect who devoted himself to the ship's design.

"I'm full of a complex mix of sorrow but gratitude and pride and hope," she said before the sinking. "He would freely admit that he loved this ship a thousand times more than my grandmother."

Gibbs said her organization concluded that reefing was "by far the more dignified solution" compared with the scrapyard.

Flynn, the diver, said the ship will retain a sense of grandeur underwater. "There's something about looking out over that bridge … and seeing the nose of the bow and then seeing just the blue out in front of it," she said. "That is going to be a spectacular shot."