The Woods Hole Oceanographic Institution team in the United States recently completed a deep-sea training and engineering mission in the waters of San Diego. Using the most advanced ocean detection equipment, it recorded the sunken site of the U.S. Navy's F-1 submarine in high definition for the first time. The submarine sank due to an accident on December 17, 1917, killing 19 crew members. It has been sleeping quietly at a depth of 400 meters underwater for more than a hundred years.

Photogrammetric reconstruction of the F-1 submarine on the seafloor west of San Diego, California. Photo credit: Zoe Dahlen/Woods Hole Oceanographic Institution

In this operation, the team of scientists relied on the National Deep Sea Diving Facility's manned submersible Alvin and autonomous underwater vehicle Sentry to conduct close exploration and image collection of the sunken ship. This mission is not only a test of some high-precision deep-sea equipment, but also a part of the training program for deep-sea scientists, which is jointly supported by the National Science Foundation and other institutions.

The scientific research team conducted detailed mapping of the submarine and its surrounding seafloor environment through the sonar system on the Sentry vehicle and the mother ship Atlantis. At the same time, the high-resolution camera system and streamer camera carried by Alvin collected a large amount of still and video data. It is worth mentioning that the wreckage of a US Army torpedo bomber from World War II was also scanned and recorded in the same area.

"Advanced marine technology and teamwork were the keys to this successful imaging," said Bruce Strickrott, the leader of the Alvin. "After we confirmed the wreck and ensured safety, we obtained a unique and detailed view of the submarine for the first time. As a Navy veteran, it is a great honor to participate in this extraordinary expedition with my companions."

The front section of the wreckage of a World War II Avenger torpedo bomber that crashed into the ocean on DATE during a training flight off the coast of Southern California. Image credit: Anna Michel, Woods Hole Oceanographic Institution; NSF GEO; Woods Hole Oceanographic Institution

This effort brings together the U.S. Office of Naval Research, the University-National Marine Laboratory System, and the Naval History and Heritage Command. Krugel, a naval historian, said, "Visiting a historical site in person is an experience that is both thrilling and awe-inspiring. We sincerely appreciate this cooperation, which allows us to truly record and assess the current status of this shipwreck."

The scientific team conducted a total of seven deep dives, not only to collect data, but also to pay tribute to the fallen officers and soldiers. After the inspection, a memorial ceremony was held on the mother ship, where bells were rung and the names of each deceased crew member were read silently, demonstrating respect for and inheritance of history.

The rapid development of imaging technology in recent years has greatly improved exploration efficiency. The multi-beam sonar system and high-resolution cameras were used together to generate a three-dimensional reconstruction model of the F-1 submarine remains and its surroundings. Marine imaging experts used photogrammetry to restore the submarine and the marine life attached to it, providing valuable information for subsequent research.

Office of Naval Research research vessel program officer Rob Sparlock, left; Naval History and Heritage Command senior archaeologist Bradley Krueger, inside the manned submersible USS Alvin. The screen in the upper right corner displays the sonar signal reflected from the hull of the F-1 submarine. Image credit: Bruce Strickrott, Woods Hole Oceanographic Institution

Chief Scientist Anna Michel said: "While these depths are within the capabilities of Alvin and Sentry, the missions have high operational and equipment requirements. We conduct exploration work carefully and strive to balance scientific value with historical awe."

The high-definition images and three-dimensional restoration models obtained from this shooting not only promote deep-sea archaeological research, but also deepen our admiration and thinking about history.

Compiled from /ScitechDaily