Over a hundred years after it vanished below the waves, the wreck of the USS F-1 has finally been seen in detail. Lost during a training accident off the coast of San Diego in 1917, the World War I-era submarine lay hidden more than 1,300 feet down, untouched by human hands since its brief, tragic final moments. Now, with the aid of cutting-edge submersible technology, the long-silent wreck has emerged in haunting clarity.

In a joint mission led by Woods Hole Oceanographic Institution (WHOI), researchers used a combination of sonar mapping and high-resolution imaging to locate and document the sunken submarine.

The expedition deployed two tools built for deep-sea exploration: the human-occupied vehicle Alvin and the autonomous underwater vehicle Sentry. These deep-diving workhorses, part of the National Deep Submergence Facility, enabled a full visual survey of the wreck site for the first time ever, as Phys.org reports.

Photo: Wikimedia Commons / U.S. Navy, License: Public Domain

The USS F-1 sank in 1917 after colliding with another submarine during training.

The Wreck Resurfaces

The USS F-1 was once called USS Carp when it was laid down in 1909. It served with the Pacific Torpedo Flotilla until its final mission in December 1917. That month, during routine exercises alongside sister submarines F-2 and F-3, all three vessels drifted into heavy fog, Task & Purpose reports. The F-3 struck the F-1 amidships. The smaller sub’s port side crumpled. Its engine room flooded. It sank in just ten seconds, claiming 19 of the 24 sailors aboard.

Though sonar had located the wreck in the 1970s during an unrelated search for a crashed aircraft, no in-depth survey was ever completed—until now. The recent dives, carried out in February and March 2025, not only confirmed the sub’s identity but also produced detailed images of its structure and surroundings. The sub was found lying on its starboard side, its conning tower and hull still intact despite more than a century of pressure and corrosion, Live Science reports.

Technology Meets Tragedy

The survey team conducted seven dives in total. The mission was part of a broader engineering and training initiative, giving new pilots time in Alvin while expanding the frontier of ocean mapping, CBS News reports.

Using Sentry’s multibeam sonar and Alvin’s cameras, they captured sweeping views of the sub and its resting place. WHOI experts then created photogrammetric 3D models of the wreck, allowing for precise measurements and digital preservation of the site.

These visuals, released by the research team, show not only the damage from the collision but also the slow colonization of the wreck by marine life over time.

The expedition also documented a second site nearby: the remains of a Navy Avenger torpedo bomber that crashed in 1950. Though known to researchers for years, this marked the first time the U.S. Navy formally documented the aircraft. As Gizmodo reports, both wrecks now serve as training platforms for deep-sea mapping and as artifacts of maritime history.

Photo: Wikimedia Commons / U.S. Navy, License: Public Domain

Nineteen of the 24 crew members aboard the F-1 were killed in the accident.

A Solemn Dive

This was more than just a research expedition. For many on board, the dive held deep personal meaning. Several team members were Navy veterans themselves. Brad Krueger, an underwater archaeologist with the Naval History and Heritage Command, made his first-ever dive in Alvin to see the wreck.

The team held a remembrance ceremony aboard the research ship Atlantis, ringing a bell 19 times—once for each sailor lost aboard F-1. Their names were read aloud on the open sea, above the place they now rest.

Krueger, along with his colleagues, emphasized the importance of preserving the wreck as a war grave. No physical contact was made with the sub. Instead, its digital twin now lives on in the hands of scientists and historians, a record of sacrifice and a portal into the early days of naval warfare.

Past, Preserved

The rediscovery of the USS F-1 is more than a technological achievement. It brings closure to a century-old tragedy and highlights the continued risks of military service. With the wreck now fully documented, future generations have a new window into a pivotal era of naval history. The silent ship, once lost to the deep, has found its voice again.