Watch Incredible Footage of Submarine Shipwreck Lost to Sea Over 50 Years Ago

Footage of a diving expedition that revealed the wreckage of a World War II-era U.S. submarine has been released by the National Oceanic and Atmospheric Administration (NOAA).

The video clip, released by the NOAA in July and posted to Facebook on Tuesday, shows how NOAA officers sent a remote underwater robot to the seabed after being alerted to a potential shipwreck by the U.S. military's Naval History and Heritage Command (NHHC).

Sending the robot more than 2,000 feet underwater, the NOAA was able to identify the wreckage of the ex-USS Muskallunge, a veteran Gato-class submarine that served between 1942 and 1968.

During active service the submarine had been used by the U.S. Navy to attack Japanese convoys including passenger freighters and cargo ships, according to the NHHC.

After more than two decades of military use, including several years spent with the Brazilian navy as Humaitá (S14) following a transfer, the Muskallunge was eventually sunk as a practice target during a live-fire training exercise off the coast of New York—a fate met by other old U.S. submarines too as newer, nuclear-powered models entered service.

According to the NOAA, the Muskallunge had been torn in two by a torpedo detonation and sank quickly afterwards, with parts of the submarine imploding as it sank through pressure levels that far exceeded what it was designed for.

By the time it hit the seabed, the submarine had reached a depth more than six times its wartime-rated crush depth, and thick steel "was dented like a soda can," the NOAA wrote in a press release.

Yet the wreckage could still be clearly identified as the Muskallunge with the white letters S14 still visible on its hull, indicating its use in the Brazilian navy.

Once used as a war vehicle, the submarine has now become a sort of artificial reef, covered in colonies of bubblegum coral, sponges, and numerous fish and squid.

The NOAA mission to find the submarine was the final part of the 2021 ROV Shakedown expedition, in which remotely operated vehicles were tested at depths of thousands of meters. The expedition ran from June 13 to June 27.

"The largest museum of lost ships is the sea," the NOAA said in a press release. "And this final dive of the expedition provided an excellent opportunity to try to visit one of its millions of shipwrecks up-close, for the first time."

Following that expedition the NOAA conducted the 2021 North Atlantic Stepping Stones: New England and Corner Rise Seamounts expedition from June 30 to July 29 in order to collect information on unknown and poorly understood deepwater areas off the eastern U.S. coast.

The submarine find isn't the only NOAA footage to be released this year. The agency also released footage of a rarely-filmed deep sea squid recently.