A frogman is someone who is trained in scuba diving or swimming underwater in a tactical capacity that includes military, and in some European countries, police 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 and member of the OSS Maritime Unit, to have been applied to him while he was training in a green waterproof suit.
The Clearance Diving Branch is the specialist diving unit of the Royal Australian Navy (RAN) whose versatile role covers all spheres of military diving, and includes explosive ordnance disposal and maritime counter-terrorism. The Branch has evolved from traditional maritime diving, and explosive ordnance disposal, to include a special operations focus.
Professional diving is underwater diving where the divers are paid for their work. Occupational diving has a similar meaning and applications. The procedures are often regulated by legislation and codes of practice as it is an inherently hazardous occupation and the diver works as a member of a team. Due to the dangerous nature of some professional diving operations, specialized equipment such as an on-site hyperbaric chamber and diver-to-surface communication system is often required by law, and the mode of diving for some applications may be regulated.
Underwater divers may be employed in any branch of an armed force, including the navy, army, marines, air force and coast guard. Scope of operations includes: search and recovery, search and rescue, hydrographic survey, explosive ordnance disposal, demolition, underwater engineering, salvage, ships husbandry, reconnaissance, infiltration, sabotage, counterifiltration, underwater combat and security.
The Republic of Singapore Navy (RSN) is the maritime service branch of the Singapore Armed Forces (SAF) responsible for defending the country against any seaborne threats and as a guarantor of its sea lines of communications. The RSN traces its origins to the Royal Navy when Singapore was still a crown colony of the British Empire. The service was formally established in 1967, two years after its independence from Malaysia in 1965, and had undergone a substantial modernisation ever since – which has led them into becoming the most powerful navy in Southeast Asia.
The Naval Special Warfare Command, commonly known as the Royal Thai Navy SEALs, is the special operations force of the Royal Thai Navy.
A clearance diver was originally a specialist naval diver who used explosives underwater to remove obstructions to make harbours and shipping channels safe to navigate, but the term "clearance diver" was later used to include other naval underwater work. Units of clearance divers were first formed during and after World War II to clear ports and harbours in the Mediterranean and Northern Europe of unexploded ordnance and shipwrecks and booby traps laid by the Germans.
A United States Navy diver refers to a service personnel that may be a restricted fleet line officer, civil engineer corps (CEC) officer, Medical Corps officer, or an enlisted 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 Special Warfare Group (SWG) is the primary special forces unit of the Republic of Singapore Navy (RSN) responsible for conducting special operations from sea, air, and land. It is one of six squadrons of the Naval Diving Unit (NDU).
The Naval Special Operations Command (NAVSOCOM) is a separate command of the Philippine Navy trained in special operations, sabotage, psychological and unconventional warfare and is heavily influenced by the United States Navy SEALs. NAVSOCOM is headquartered at Naval Base Heracleo Alano Sangley Point, Cavite City. It has eleven units located across the Philippines, from Naval Operating Base San Vicente at Santa Ana, Cagayan in the north to Naval Station Zamboanga in the south.
Minedykkerkommandoen (MDK) or Norwegian Naval EOD Command is a clearance diver group. MDK is subordinate to the Royal Norwegian Navy. MDK is located at Haakonsvern Naval Base in Bergen and Ramsund Naval Base, in vicinity of Harstad.
The Divers Group is the Portuguese Navy's sapper clearance diver unit. It was created in 2004 through the grouping of the several already existing diving subunits, to exercise administrative, logistical and operational control and management, maritime special operations capable, over all diver units and personnel. It groups under a single command, all previously existing Sappers Divers Units and Services.
Canadian Armed Forces (CAF) divers are specialists trained to conduct underwater operations within their respective environmental commands. Divers within the CAF are qualified into sub-categories of diving. Be it a member of a diving team or a CAF member who is maintaining currency and qualification through casual diving. Divers within the CAF are trained as Clearance Divers, Search and Rescue Technicians (SAR), Port Inspection Divers (PID), Ship's Team Divers, and Combat Divers.
The US employs divers in several branches of the armed forces, including the navy, army, marines, air force and coast guard.
The USMC Combatant Diver Course is taught at the Navy Diving and Salvage Training Center, Naval Support Activity Panama City, Panama City, Florida. Both of the Marine Air-Ground Task Force reconnaissance assets, FMF Recon and MarDiv Recon, widely use combatant diving. During this eight-week course, trainees are introduced to open and closed-circuit diving, diving physics and medical aid. Most of the training in combatant diving is done at night.
The Special Operations Task Force (SOTF) is a special operations command of the Singapore Armed Forces (SAF) responsible for conducting special operations. The SOTF is composed of only highly-trained regular servicemen from the Army's Special Operations Force (SOF) under the Commandos formation and, the Navy's Special Warfare Group (SWG) under the Naval Diving Unit (NDU).
The Special Task and Rescue Team, abbreviated as STAR, serves as the command for elite maritime special operations and underwater divers within the Malaysia Coast Guard. It was established as a rapid reaction force for emergencies within the maritime zone of Malaysia.
Naval Special Forces Command, also called the Kampfschwimmer or Verwendungsgruppe 3402 are an elite special forces unit of the German Navy, specializing in commando and amphibious warfare operations. They are the only special-purpose force of the German Navy. The Kampfschwimmer were set up when West Germany joined NATO in 1955.
Underwater Construction Teams (UCT) are the United States Navy Seabees' underwater construction units numbered 1 and 2 that were created in 1974. A team is composed of divers qualified in both underwater construction and underwater demolition. Possible tasks can be: battle damage repairs, structural inspections and assessments, demolition of waterline facilities or submerged obstructions, installation of submerged surveillance systems, or harbor and channel clearance. As needed, teams may test and or evaluate new or existing aquatic systems or equipment. Extending construction, whether vertical or horizontal, beyond the shoreline and waterline is their specialty. Reflecting Seabee tradition, teams are expected to execute underwater construction anywhere, anytime, under any conditions.
Singapore 
Republic of Singapore Navy 
