A frogman is someone who is trained in scuba diving or swimming underwater in a tactical capacity that includes police or military work. Such personnel are also known by the more formal names of combat diver, combatant diver, or combat swimmer. The word frogman first arose in the stage name The Fearless Frogman of Paul Boyton in the 1870s and later was claimed by John Spence, an enlisted member of the U.S. Navy, to have been applied to him while he was training in a green waterproof suit.
The term frogman is occasionally used to refer to a civilian scuba diver. Some sport diving clubs include the word Frogmen in their names. The preferred term by scuba users is diver, but the frogman epithet persists in informal usage by non-divers, especially in the media and often referring to professional scuba divers, such as in a police diving role.
In the U.S. military and intelligence community, divers trained in scuba or CCUBA who deploy for tactical assault missions are called "combat divers". This term is used to refer to the Navy SEALs, operatives of the CIA's Special Activities Division, elements of Marine Recon, Army Ranger Regimental Reconnaissance Company members, Army Special Forces divers, Air Force Pararescue, Air Force Combat Controllers, U.S. Coast Guard Helicopter Rescue Swimmers, United States Naval Search and Rescue Swimmers, United States Air Force Special Operations Weather Technicians, and the Navy Explosive Ordnance Disposal (EOD) units. In Britain, police divers have often been called "police frogmen".
Some countries' tactical diver organizations include a translation of the word frogman in their official names, e.g., Denmark's Frømandskorpset; others call themselves "combat divers" or similar. Others call themselves by indefinite names such as "special group 13" and "special operations unit".
Many nations and some irregular armed groups deploy or have deployed combat frogmen.
Tactical diving is a branch of professional diving carried out by armed forces and tactical units. They may be divided into:
Special mission work divers (called Clearance Divers in the British Royal Navy and Royal Australian Navy), who do general work underwater.
Work divers who are trained in defusing mines and removing other explosives underwater.
These groups may overlap, and the same men may serve as assault divers and work divers, such as the Australian Clearance Diving Branch (RAN).
The range of operations performed by these operatives includes:
Amphibious assault: stealthy deployment of land or boarding forces. The vast majority of combat swimmer missions are simply to get "from here to there" and arrive suitably equipped and in sufficient physical condition to fight on arrival. The deployment of tactical forces using the arrival by water to assault land targets, oil platforms, or surface ship targets (as in boardings for seizure of evidence) is a major driver behind the equipping and training of combat swimmers. The purposes are many, but include feint and deception, counter-drug, law enforcement, counter-terrorism, and counter-proliferation missions.
Sabotage: This includes putting limpet mines on ships.
Clandestine surveying: Surveying a beach before a troop landing, or other forms of unauthorized underwater surveying in denied waters.
Clandestine underwater work, e.g.:
Recovering underwater objects.
Clandestine fitting of monitoring devices on submarine communications cables in enemy waters.
Investigating unidentified divers, or a sonar echo that may be unidentified divers. Diving sea-police work may be included here. See anti-frogman techniques.
Checking ships, boats, structures, and harbors for limpet mines and other sabotage; and ordinary routine maintenance in war conditions. If the inspection divers during this find attacking frogmen laying mines, this category may merge into the previous category.
Underwater mine clearance and bomb disposal.
Typically, a frogman with closed circuit oxygen rebreathing equipment will stay within a depth limit of 20 feet (6.1 m) with limited deeper excursions to a maximum of 50 feet (15 m) because of the risk of seizure due to acute oxygen toxicity. The use of nitrox or mixed gas rebreathers can extend this depth range considerably, but this may be beyond the scope of operations, depending on the unit.