A United States Navy diver refers to a service personnel that may be a restricted fleet line (Engineering Duty) officer, civil engineer corps (CEC) officer, Medical Corps officer, or an enlisted (ND or HM rating) who is qualified in underwater diving and salvage. Navy divers serve with fleet diving detachments and in research and development. Some of the mission areas of the Navy diver include: marine salvage, harbor clearance, underwater ship husbandry and repair, submarine rescue, saturation diving, experimental diving, underwater construction and welding, as well as serving as technical experts to the Navy SEALs, Marine Corps, and Navy EOD diving commands.

The U.S. Navy is the lead agency in military diving technology and training within the U.S. Department of Defense. The foundation of the Navy diving program consists of the Navy Diver (ND) rating for enlisted personnel who perform diving as their occupational specialty in the Navy.

Navy diver (United States Navy)

History through World War II

The US Navy began employing divers in the middle of the 1800s; these were mostly swimmers and skin divers using techniques that had not been altered for hundreds of years. Duties included the salvage and repair of ships, construction work and military operations, including the Battle of Mobile Bay during the American Civil War. Preparations for the battle included the sending of swimmers to clear mines from the path of Admiral Farragut's ships, that had been planted by Confederate States forces to prevent entrance to the bay.

Navy diver (United States Navy)

In 1898, Navy divers were briefly involved in an international crisis when the second-class armored battleship 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.

Navy diver (United States Navy)

As American technology expanded in the early 1900s the US Navy developed an interest in submarine warfare. However, throughout the period of 1912–1939, the development of the Navy's F-class, H-class and S-class submarines was marred by a series of accidents, collisions, and sinkings. As a result of these submarine disasters a corresponding growth in the Navy's diving capability was developed.

Until 1912, US Navy divers rarely went below 60 FSW (feet of seawater). There is little documentation that the Navy had a diving program prior to 1912. 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 , Navy divers went progressively deeper.

The publication of the first US Navy Diving Manual in 1916 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 salvage. When the United States entered World War I, the staff and graduates of the school were sent to Europe, where they conducted a number of salvage operations along the French coast.

On 24 May 1939 four divers would earn the Medal of Honor rescuing 33 men off the sunken . When the Squalus went down twelve divers from the Experimental Diving Unit were part of the rescue. Those directly involved in the most dangerous aspects of the rescue received the medals.