Reef Program Dodges a Bullet

SS United States Finally Leaves Philadelphia to Begin Its Last Chapter

By Forrest Brown and Danny Freeman, CNN
Wed February 19, 2025

The storied ocean liner SS United States leaves its Philadelphia pier in the Delaware River on Wednesday. From SS United States Conservancy/Facebook

After months of multiple delays, the SS United States finally left its longtime home of Philadelphia just before 1 p.m. ET Wednesday. The storied ocean liner's next stop is Mobile, Alabama, where it will be prepared for its final mission - to become an artificial reef off the coast of the Florida Panhandle. The American maritime icon, nearly as large as the Chrysler Building, was launched in 1951 and set the transatlantic speed record in 1952.

"Today, the nation's sole surviving ocean liner will glide down the Delaware River to begin the next chapter in her uniquely American story," said Susan Gibbs, president of the SS United States Conservancy and granddaughter of the ship's designer, William Francis Gibbs, in statement just before ship left. After spending nearly three decades docked empty in Philadelphia, the tow to Mobile is expected to take about two weeks.

A Series of Delays

The SS United States spent decades in Philadelphia before its departure on Wednesday. CNN

Observers of the SS United States' move had become accustomed to changes of plans. Last fall, the biggest hurdle came in the form of a "Captain of the Port Order" from the Coast Guard. The order said Florida's Okaloosa County, which is receiving the ship, needed to restore the ship's structural integrity before it would be allowed to depart. It was all set to go on February 6 when departure was again postponed "due to follow-up details requested by the U.S. Coast Guard to ensure a proper tow from Pier 82 to Pier 80."

New Mission: Artificial Reef

In the fall of 2024, Okaloosa County bought the ship to sink her and create the "world's largest artificial reef." The ship's final home will be under about 180 feet (55 meters) of water out about 20 miles (32 kilometers) in the Gulf of Mexico. For more than 70 years, the SS United States captivated the hearts and minds of Americans for her distinguished beauty. Among its passengers: multiple US presidents and Leonardo da Vinci's "Mona Lisa." She was withdrawn from service in 1969.

The admiration never ceased, and the ship's final fate has brought mixed emotions. "(It's) heartbreaking to see it go," said Kelly Micca in November. Micca spent several weeks painting a picture of the SS United States on an electrical pole across from the pier. "It's such a perfect landmark." On Wednesday, one commenter on the SS United States Conservancy's Facebook page said, "Poor gal deserved a better fate than what she's about to receive. The scuba videos will be interesting though."

The mutilated USS Radford broke apart shortly after sinking.
I can find no report of anyone going to the site since 2012!

The USS Radford paralyzed the Artificial Reef Programs of three states for over a year, to create a million-dollar pile of rubble too far offshore for anyone to bother with. The United States would have been an even bigger debacle, I am relieved to see it go. Such huge reefs far offshore might work in the Gulf of America, but not in the stormy and unpredictable North Atlantic. It's just common sense.


The proper way to fill a scuba cylinder is very slowly so that the heat generated by the filling process can be bled away as it happens, and the tank does not become overheated. That's a great theory, but in real life, nobody does it that way. Most tanks are "hot-filled", that is to say, that they are filled too fast to prevent them from heating up during the process. If they are filled directly off a compressor, then they will receive a very hot fill. You would be surprised how warm the surface of a tank can get. This is not much of a safety issue, though, as it is well within the thermal limits of the material, either aluminum or steel.

The real issue here is that eventually ( after a few hours ) the tank will cool down, and as it does, the air inside will contract, and the pressure will drop. This typically results in about a 10% loss of pressure. At this point, you could top it off to the rated pressure again and have a truly full tank. Most of the time that's not an option. Therefore, if the shop hot-fills your tank to 3000, you will end up with 2700. To get 3000, you need to fill the tank to about 3300. While this is verboten, it is well within the 5/3 overpressure of the hydro test, and realistically there is no danger. The slight overpressure may wear out your o-rings a little faster, but o-rings are cheap - get a dozen of them at the hardware store for a buck.