“Operating at sea has always been inherently dangerous, and even more so for early submarines.” These are the words of Sam J. Cox, retired U.S. Navy rear admiral and head of the Naval History and Heritage Command, resonate with special solemnity in light of the recent find of the USS F-1 submarine, missing for more than a century and now discovered surprisingly well-preserved at a depth of more than 1,300 feet off San Diego. The operation, a collaboration between the Woods Hole Oceanographic Institution (WHOI) and the U.S. Navy, and this is a testament to the development of marine technology as well as the timelessness of naval history.
The history of the USS F-1 is as abrupt as it is fatal. On December 17, 1917, the F-1 was making a 48-hour engineering cruise between San Pedro and San Diego, with her sister boats, F-2 and F-3, in tow. All three ships penetrated a thick blanket of fog off Point Loma. With the chaos, the F-3 crashed into the F-1, ripping a devastating hole just astern of the conning tower. The F-1 sank within nine seconds, taking 19 of 24 crewmen with it. Testimony of survivors and accounts for years had created a picture of tragedy, but only through present technology could the complete story be mapped out on the seafloor.
The recent voyage was as much about unearthing history as it was a demonstration of engineering expertise. The site, at over 1,300 feet below the surface, is well out of reach of standard divers. Rather, the WHOI team utilized the autonomous underwater vehicle (AUV) Sentry, outfitted with side-scan and multi-beam sonar, to systematically survey the region. Sentry’s technical strengths untethered operation, wide seafloor coverage, and high-resolution sonar returns allowed it to find the F-1 wreck on the first afternoon of searching.
After Sentry had identified the wreck, the human-occupancy vehicle (HOV) Alvin followed it down. Alvin, a deep-sea exploration legend, has been recently upgraded and certified by Naval Sea Systems Command. Equipped with high-definition and 4K cameras, Alvin was tasked to capture detailed images for the production of three-dimensional photogrammetric models. Pilots of the sub, certified by Submarine Development Squadron Five, conducted an eight-hour dive, carefully documenting the site and photographing the submarine’s conning tower, periscopes, wheel, and hatches. “The submarine’s conning tower, periscopes, wheel, and hatches are all present, much as they were the same day the sub was lost,” as penned by NHHC archaeologist Bradley Krueger.
The physical condition of the F-1 is impressive. The ship rests on its starboard side, bow facing northwest, with most features remaining intact in their original orientations. The greatest damage a great oval hole on the port side supports survivor testimony and indicates where the killing collision occurred. The fairing superstructure over the pressure hull exhibits more decay, but the wreck as a whole remains a time capsule, undisturbed for more than a century.
The scope of the expedition went beyond the F-1. Close to the submarine, the crew examined the wreck of a Grumman TBM Avenger torpedo bomber that had gone down while on a training flight in October 1950 after engine failure off La Jolla. The Avenger lies upright, wings splayed, fuselage and tail basically intact, and even the cockpit glass and canopy still in position proof that the pilot had managed to clear out before the aircraft sank. The national insignia of the aircraft and the number “13” stencilled on the engine nacelle presented key identification clues.
The expedition was as much an exercise in technological ingenuity as it was one in history. Alvin’s direct human observation and control, paired with Sentry’s autonomous mapping and reconnaissance, are the pinnacle of deep-sea exploration technology. Through the application of photogrammetric modeling and high-resolution photography, scientists are able to not only record these locations for the ages but also build precise virtual reconstructions to be explored and shared further.
The efforts of the WHOI-led expedition ended in a somber remembrance ceremony on the research vessel Atlantis. Over the grave of the F-1, the captain read off the names of the 19 lost sailors, each name punctuated by the clanging of the ship’s bell.
While the U.S. As Navy anticipates its 250th birthday, the effort of the NHHC Underwater Archaeology Branch and its collaborators remains ongoing. With the responsibility to protect nearly 3,000 shipwrecks and more than 18,000 aircraft wrecks, the branch uses a combination of traditional skills and the most recent advances in marine engineering to conserve and interpret the Navy’s submerged cultural heritage. The finds off San Diego remind us of both the dangers confronting seamen and the wonderful advances in technology that enable us to pay tribute and learn from the past.
