This Submarine Sank Over 100 Years Ago – Here's How It Was Finally Found

Submarines have been around since the 17th century, and while we know much about modern nuclear subs, the older boats are less well known. This is especially true of those used during World War I, as the second global conflict had much more submarine activity than its predecessor. The United States Navy began using submarines in 1900 with the commissioning of the USS Holland (SS-1). Many more followed, including the USS F-1 (SS-20; originally named the USS Carp), which was commissioned in 1912.

As you can tell from the naming convention, the F-1 was the 20th submarine operated by the U.S. Navy. The F-1 served for several years in the lead-up to WWI, though the boat was decommissioned in 1916. With WWI raging across the pond, submarines were needed, and the F-1 was returned to active service in 1917, operating out of its base in San Pedro, California. On December 17, 1917, the F-1 met its fate during an exercise. The boat collided with the F-3 (SS-22) and sank in ten seconds, taking 19 of the 24 crew to the bottom of the sea.

The Woods Hole Oceanographic Institution rediscovered the F-1 resting on the seafloor around 1,300 feet below the surface using a survey of Navy records. While this discovery was made in 2025, it wasn't the first time the wreck was found. The U.S. Navy's oceanographic research vessel, the USNS De Steiguer (T-AGOR-12), found it while looking for a lost aircraft in October 1975. Instead, it located the F-1, but didn't conduct a detailed survey.

It's not uncommon for the site of a naval wreck to be lost — especially during wartime. Organizations like the Woods Hole Oceanographic Institution (WHOI) go out and find what they can, including the F-1. Not only was the F-1 found using old survey records from 1975 that hadn't been examined for 50 years, but it was located near a plane. It was not the same plane that the USNS De Steiguer was looking for in 1975.

Instead, it was a U.S. Navy Grumman TBF Avenger torpedo bomber that was lost in 1950. While the Navy found the wreck in '75, it kept this information classified from the public. Still, despite knowing where to find it, no surveys were conducted until WHOI went out and took high-definition imagery. The F-1 was found lying on its starboard side and was almost completely intact. The images show the wreck almost as it might have looked had it been floating on the surface.

Because of the depth, diving wasn't an option, so digital imagery via submersible robots was taken alongside sonar data to build a complete picture. While it wasn't the worst submarine disaster in history, the sinking of the F-1 was an early blow to the Navy's submarine force. The F-1's loss was the only submarine the U.S. lost during WWI, and it didn't involve any enemy action. It was an accident that ended the F-1 and cost the lives of 19 submariners.