The early history of diving in the US Navy parallels that of the other navies of the world. Since the middle of the nineteenth century, the Navy has employed divers in salvage and repair of ships, in construction work, and in military operations.
For the most part, early Navy Divers were swimmers and skin divers, with techniques and missions unchanged since the days of Alexander the Great. During the Civil War Battle of Mobile Bay, swimmers were sent in ahead of Admiral Farragut's ships to locate and disarm Confederate mines that had been planted to block the entrance to the bay.
In 1898, Navy Divers were briefly involved in an international crisis when the second-class armored battleship USS Maine was sunk by a mysterious explosion while anchored in the harbor at Havana, Cuba. Navy Divers were sent from Key West to study and report on the wreck. Although a Court of Inquiry was convened, the reason for the sinking was not found.
The beginning of the twentieth century saw the attention of all major navies turning towards developing a weapon of immense potential - the military submarine. The highly effective use of the new weapon by the German Navy in World War I heightened this interest, and an emphasis was placed on the submarine that continues today.
The US Navy had operated submarines on a limited basis for several years prior to 1900. As American technology expanded, the US submarine fleet grew rapidly. However, throughout the period of 1912-1939, the development of the Navy's F, H, and S class boats was marred by a series of accidents, collisions, and sinkings. Several of these submarine disasters resulted in a correspondingly rapid growth in the Navy diving capability.
Until 1912, US Navy Divers rarely went below 60 fsw (feet of seawater). In that year, Chief Gunner George D. Stillson set up a program to test Haldane's diving tables and methods of stage decompression. A companion goal of the program was to develop improvements in Navy diving equipment. Throughout a three-year period, first diving in tanks ashore and then in open water in Long Island Sound from the USS Walke (Destroyer No.34), the Navy Divers went progressively deeper, eventually reaching 274 fsw.
The publication of the first US Navy Diving Manual and the establishment of a Navy Diving School at Newport, Rhode Island were the direct outgrowth of experience gained in the test program and the USS F-4 salvage. When the United Stares entered World War I, the staff and graduates of the school were sent to Europe, where they conducted various salvage operations along the French coast.