In 1917, two US submarines collided off the coast of San Diego and submarine USS F-1 sank to the bottom of the Pacific Ocean, along with 19 crew members aboard. The horrible accident, whose wreckage was discovered in 1975, represents the US Naval Submarine Force’s first wartime submarine loss. Now, researchers from Woods Hole Oceanographic Institution have captured new footage of the 1,300 feet-deep underwater archaeological site. Photogrammetric reconstruction of the submarine USS F-1 showing the sub’s stern and propeller. CREDIT: Image by Zoe Daheron, ©Woods Hole Oceanographic Institution.