The SS United States takes its final voyage to the bottom of the Gulf of Mexico

Retired passenger liner SS United States is pictured at a dock in Philadelphia, Pennsylvania. The SS United States still holds the east- and west-bound transatlantic crossing records. AFP PHOTO/JEWEL SAMAD (Photo credit should read JEWEL SAMAD/AFP via Getty Images) JEWEL SAMAD/AFP via Getty Images/AFP hide caption

JEWEL SAMAD/AFP via Getty Images/AFP

A giant ship sunk off the coast of Florida yesterday—and the coast guard didn't do a thing to stop it.

The SS United States is a retired ocean liner that was deliberately sunk on Wednesday to create the world's largest artificial reef. After hours of slow descent, it finally disappeared beneath the waves at 10 p.m. ET last night. It now rests 180 feet beneath the surface at the bottom of the Gulf of Mexico in an upright position.

Measuring almost 1,000 feet from bow to stern, the giant ship is longer than the Titanic. After it's settled on the ocean floor, the ship's hundreds of rooms, corridors and elevator shafts will become a deep-sea playground for divers, fish and other aquatic life.

This transformation gives the SS United States the opportunity for a second life and a new species of passenger.

Susan Gibbs has mixed feelings about the ship's final voyage to the bottom of the Gulf of Mexico. She chairs the board of the SS United States Conservancy, and her grandfather, William Francis Gibbs, designed the ship more than 70 years ago.

"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," she told Morning Edition

The ocean liner took its maiden voyage in 1952, and it shattered the trans-Atlantic speed record, winning the coveted Blue Riband on her opening sail. It still holds the record more than 60 years later.

In the event of war, the SS United States could have been converted from a luxury liner to a military transport vessel able to carry 14,000 troops for 10,000 miles without refueling, though it was never used for this purpose, according to the SS United States Conservancy.

1952: Cheering crowds lining the quayside as the record breaking liner, SS United States arrives in Southampton. She crossed the Atlantic in record time on her maiden voyage. (Photo by M. Fresco/Topical Press Agency/Getty Images) M. Fresco/Getty Images/Hulton Archive hide caption

M. Fresco/Getty Images/Hulton Archive

By the end of her time on the water in 1969, the SS United States carried several notable passengers, including Harry Truman, Walt Disney, Marilyn Monroe, Walter Cronkite and a young Bill Clinton.

"She embodied the spirit of a nation so confident in its ability to accomplish the extraordinary," said Gibbs.

The conservancy wanted to transform the ship into a hotel or museum, but due to legal and financial issues, they eventually sold it to Okaloosa County, Florida in 2024. It was the county's decision to sink it.

Realistically, it's not easy to sink something that's designed to stay above water. So, Okaloosa County called in the professionals.

Coleen Marine, a marine engineering contracting company who specializes in creating artificial reefs, led the project. Their President and co-founder Coleen O'Malley said they did their best to preserve the ship's original design.

"We've maintained the actual hull. So she's very recognizable," O'Malley said. "We've made it so that the structure under the water is going to look like she did above the water."

To sink the ship, the Coleen Marine team had to repair holes and irregularities in the hull to ensure it would sink properly. O'Malley detailed that "the biggest thing with sinking a ship is not how much water you put in. It's making sure the air comes out."

The team also cleaned much of the rusted exterior to make a more welcoming environment for aquatic life. Most importantly, the team wanted to ensure that the ship sank straight down, without flipping or turning. Overall, O'Malley said construction took more than 18 months.

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

In the wake of its last moments above the surface, the SS United States Conservancy is planning to construct a museum in the ship's honor in Florida.