USS Squalus (SS-192) Salvage Operations, 1939
Air comes to the surface during blowing of salvage pontoons to lift Squalus off the sea bottom, 12 August 1939. There were separate groups of pontoons supporting the sunken submarine's bow and stern. Three pontoons were located at the top of the lift line in each location and surfaced during the 12 August lift. One more pontoon remained underwater on the bow line and three more on the stern line when this lift was completed. Photographed by the Portsmouth Navy Yard, Kittery, Maine. Official U.S. Navy Photograph, from the collections of the Naval History and Heritage Command.