SS United States sinks 180 feet below Gulf of Mexico

By Marcus Bennett

The SS United States sank upright 180 feet beneath the Gulf of Mexico at 10 p.m. ET on Wednesday, becoming the world's largest artificial reef off Florida, according to the SS United States Conservancy.

The retired ocean liner disappeared after hours of slow descent. Morning Edition reported that the U.S. Coast Guard did not stop the operation.

Okaloosa County chose to sink the ship after buying it from the conservancy in 2024.

What does the reef change for divers and marine life?

According to the SS United States Conservancy, the vessel measured almost 1,000 feet from bow to stern, making it longer than the Titanic. Its hundreds of rooms, corridors and elevator shafts will become a deep-sea playground for divers, fish and other aquatic life.

The transformation gives the liner a second life and a new class of passenger: the fish and other aquatic life expected to inhabit its interior spaces.

Coleen Marine also cleaned much of the rusted exterior to make the wreck more welcoming to aquatic life. The company sought to leave the ship's familiar structure visible within the new reef.

How did engineers prepare the liner for an upright descent?

Coleen Marine, a marine engineering contracting company that specializes in creating artificial reefs, led the preparation and sinking of the vessel off Florida.

Its president and co-founder, Coleen O'Malley, said the team maintained the actual hull and aimed to make the submerged structure resemble its above-water form.

“The biggest thing with sinking a ship is not how much water you put in. It's making sure the air comes out,” O'Malley said.

The team repaired holes and irregularities in the hull before the descent. It also controlled the liner's air so the vessel could sink properly, without flipping or turning.

O'Malley said construction took more than 18 months. The team worked to ensure the ship went straight down in an upright position.

A record-breaking life at sea

Susan Gibbs chairs the SS United States Conservancy. Her grandfather, William Francis Gibbs, designed the ship more than 70 years ago, and Gibbs has mixed feelings about its final voyage.

“It's a combination of grief, that I will be saying goodbye to her in her current form, but, gratitude and hope in terms of what she will continue to give to the world,” Gibbs told Morning Edition.

The liner made its maiden voyage in 1952 and shattered the trans-Atlantic speed record. It won the Blue Riband on its opening sail, a record the conservancy says it still held more than 60 years later.

According to the SS United States Conservancy, the ship could have become a military transport for 14,000 troops over 10,000 miles without refueling. It never carried troops in wartime.

The liner ended its service on the water in 1969. The conservancy lists these notable passengers from its career:

• Harry Truman
• Walt Disney
• Marilyn Monroe
• Walter Cronkite
• A young Bill Clinton

Gibbs argued that the vessel embodied a nation confident in its ability to achieve the extraordinary.

The museum plan after the sinking

The conservancy wanted to turn the ship into a hotel or museum. Legal and financial problems prevented that plan, so it sold the vessel to Okaloosa County, Florida, in 2024, and the county chose to sink it.

O'Malley and Gibbs traveled to the coast of Destin and Fort Walton Beach to watch the SS United States disappear below the waves on Wednesday.

After the ship's final moments above the surface, the conservancy said it was planning to construct a museum in its honor in Florida.

The planned Florida museum will preserve the liner's history, while the offshore wreck will serve as the habitat its conservancy intended. Together, those projects define the conservancy's next phase.