In a remarkable blend of cutting-edge technology, historical curiosity, and deep-sea exploration, a recent expedition has uncovered the most detailed imagery ever captured of the USS F-1 submarine—more than a century after it sank off the coast of San Diego in 1917.

PH๏τogrammetric reconstruction of the submarine USS F-1 on the seafloor west of San
Diego, Calif. Credit: Zoe Daheron, ©Woods Hole Oceanographic Insтιтution

The World War I-era vessel went down during a training accident, taking 19 crew members with it. Now, in a series of coordinated dives, researchers have produced stunning 3D models and high-definition pH๏τographs of the wreck, lying at 400 meters beneath the surface.

Between February 24 and March 4, the Woods Hole Oceanographic Insтιтution (WHOI) undertook the mission as part of a standard engineering and training cruise aboard the research vessel Atlantis. Using the human-occupied submersible Alvin and the autonomous underwater vehicle Sentry, both owned by the National Deep Submergence Facility (NDSF), the team performed seven dives to map and pH๏τograph the wreck.

Although the primary purpose of the cruise was to train new pilots and test equipment, the opportunity to visit the F-1 wreck site gave the mission an additional powerful historical dimension.

External ship’s wheel located on the sail of USS F-1. Image courtesy of Bruce Strickrott,
Woods Hole Oceanographic Insтιтution; Funder: NSF; ©Woods Hole Oceanographic
Insтιтution

For Naval History and Heritage Command (NHHC) archaeologist Brad Krueger, it was his first Alvin dive and his first dive on a historical wreck site. “It was an incredibly exciting and humbling experience,” Krueger said. “It enabled us to document the location and honor the sacrifice of these brave American sailors.”

High-resolution seafloor maps were developed by Sentry and Atlantis’s multi-beam sonar, and Alvin’s imaging systems captured stills and video, later processed into high-resolution pH๏τogrammetric models by WHOI specialists. The models preserve the submarine digitally and also reveal its structural state.

PH๏τogrammetric reconstruction of the submarine USS F-1 showing the sub’s stern and propeller. Credit: Zoe Daheron, ©Woods Hole Oceanographic Insтιтution

The collaboration involved a number of different insтιтutions, including the National Science Foundation (NSF), the Office of Naval Research (ONR), and the University-National Oceanographic Laboratory System (UNOLS). Lisa Clough, acting director of NSF’s Division of Ocean Sciences, said: “Although these technologies are critical for revealing deep-sea geologic hazards and studying remote ecosystems, they also help us uncover crucial moments in American naval history.”

The mission culminated in a poignant memorial ceremony aboard Atlantis, where a bell was rung 19 times in memory of the sailors who perished.

More information: Woods Hole Oceanographic Insтιтution