A frogman is someone who is trained to dive or swim in a military capacity, often in combat. Such personnel are also known by the more formal names of combat diver or combat swimmer. Strictly speaking, "combat swimming" refers to surface swimming without a breathing apparatus for the purposes of coastal or ship infiltration, which is a traditional form of "frogman" activity and is thus an important feature of naval special operations. [1]
In popular usage, the term '"frogman" might also refer to a civilian scuba diver. The word arose around 1940 from the appearance of a diver in shiny wetsuit and large fins. Though the preferred term by scuba users is "diver", the "frogman" epithet persists in informal usage by non-divers, especially in the media and often in reference to professional scuba divers such as in a police role. Also, some sport diving clubs include the word "Frogmen" in their names.
In the US Military, divers trained in scuba or CCUBA who deploy for military assault missions are called "combat swimmers". This term is used to refer to the Navy SEALs, the Marine Recon swimmers, the Army Ranger swimmers, and the Navy Explosive Ordnance Disposal (EOD) units.
In Britain, police divers have often been called "police frogmen". The first British police diver was a policeman who, needing to search underwater for evidence or a body, did not use a drag but went home and fetched his sport scuba gear. See also Ian Edward Fraser.
Some countries' frogman organizations include a translation of the word "frogman" in their official names, e.g. Denmark's "Frømandskorpset" and Norway's "Froskemanskorpset"; 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.
The USMC Combatant Diver Course is created for that reason. [2] The course is taught at the Navy Diving and Salvage Training Center in Panama City, FL. During this eight-week course that they are introduced to open and the closed-circuit diving (using the LAR-V rebreather), diving physics and medicine, to give first aid to personal or other casualties in cause of diving-related hazards. Most of the training in combatant diving is mostly done at night
This course is to provide the Marines with the best possible combat underwater tactical swimming training available and developing the skills required to successfully conduct an underwater infiltration and exfiltration required by the Marine Corps Orders pertaining the reconnaissance doctrine. The candidates will learn through classroom instructions on physical training, drown-proofing and pool familiarization. Given the confidence and capabilities as a combatant diver enables the Marines to negotiate long distance in open water infiltrating in surface and sub-surface, and learn to deal with the hazards of a "surf zone" tangle, simulating equipment malfunction; to learn how to regain control without panicking.
The purpose for learning open-circuit instills the discipline that involves in descending and ascending procedures, searching for lost, submerged equipment, and day/night surface compass swims as closed-circuit emphasizes on the sub-surface navigation infiltration and exfiltrations. The combatant divers course combines lecture, demonstration, and practical application in gas mixtures of oxygen and nitrogen and oxygen charging procedures by using the USMC Oxygen Transfer Pump System, or USMC OTPS. Upon completion of the course, the candidates are honored with the Special "B" MOS 8643.
Military diving is a branch of professional diving carried out by armed forces. They may be divided into:
These groups may overlap, and the same men may serve as assault divers and work divers, as in the Australian Clearance Diving Team (RAN).
Training armed forces divers, including combat divers, is far harder, longer, and more complicated than civilian sport scuba diver training, typically takes several weeks full-time, and the trainees must be at full armed forces fitness and discipline at the start. It needs much higher levels of fitness, and during the course there is often a high elimination rate of trainees who do not make the grade. For more details see the articles on each nation's frogman group below and their external links.
This contrasts with civilian sport scuba diving training which tends to be much more casual. The general environment at sport dives is liable to encourage what a naval diver-trainer would call "a casual tourist-type attitude to being underwater", rather than a disciplined attitude of obeying orders and not being distracted; some naval diver-trainers prefer, or will only accept, trainees who have no previous scuba diving experience. [1]
For example, the PADI Open Water Diver (the most basic rank) course takes 5 dives in a swimming pool and 4 dives in open water (i.e. sea, lake, etc.); after the course the qualified diver is allowed to dive to 18 meters = 59 feet depth. The next step ( Advanced Open Water Diver) allows him to dive to 30 meters (100 feet). A further Deep Diver Speciality course allows him to dive to 40 meters (130 feet) maximum, which is considered safe for civil scuba diving: 30 m is recommended as the normal maximum. This can be compared with military frogman training courses as described in some of the articles about national military frogman bodies included or pointed to below, and their included external links.
Frogmen's breathing sets on covert operations should have particular features.
USA frogmen's rebreathers tended to have the breathing bag on the back before enclosed backpack-box rebreathers became common.
A frogman's breathing set should:
As a result, the frogman's breathing set should be fully closed circuit rebreather, preferably not semi-closed circuit and certainly not open-circuit scuba, because:
Combat frogmen sometimes use open-circuit scuba sets during training and for operations where being detected or long distance swimming are not significant concerns.
Most frogmen use a full face diving mask instead of separate mouthpiece and mask. The older type of British frogman's and naval diving mask was full face and had a mouthpiece inside it. Some frogmen use a mouthpiece and noseclip or a mouth-and-nose (oro-nasal) breathing mask instead of a diving mask with eye windows, and special contact lenses to correct the vision refraction error caused by the eyeballs being directly submerged. This is to avoid a searchlight or other lights reflecting off the mask window and thus revealing his presence, but it exposes the eyeballs to any pollution, poison, or organisms in the water.
The United States military has adopted Oceanic/ Aeris's " Integrated Diver Display Mask". It is a basic "Heads-Up Display" that lets divers monitor depth, bottom time, tank pressures, and related information while leaving their hands free for other tasks.
Another problem with a frogman who may have to come ashore and operate on land is the awkwardness of walking on land in fins, unless he plans to discard his kit and return to base by some other way than by diving, or if the frogmen plan to take and hold a position on land until other troops arrive. Some sport diving fins have the blade angled downwards for more effective swimming, but this makes walking on them more awkward.
The usual solution is for the frogman to take his fins off and carry them, but that takes time and occupies a hand carrying them unless he can clip them in to his kit or thread an arm through the fins' straps.
Another type of fin that frogmen could use would have a lockable hinge which on land can be unlocked to let the fin blade hinge up out of the way when walking.
The first type of British naval swimming fin had a short blade which was even shorter at the big toe side: this made walking on land easier for such purposes as creeping up on a sentry from behind on land, but reduced swimming speed.
The frogman's diving suit should be a tough scratch-and-cut-resistant drysuit (perhaps reinforced with kevlar), and not a soft foam wetsuit. A wetsuit can be worn under the drysuit as a warm undersuit. In very warm water, a thin tough drysuit can be worn with no undersuit.
It should not have obvious bright colored patches, unit badges or the suit's maker's advertising. Diving sea- police types, however, may find that a unit badge is useful.
Weapons that can be carried by a frogman include:
Frogmen may approach their site of operation and return to base in various ways including:
General Purpose Boat FDU(P),Yard Diving Tender (YDT) Sooke,and the YDT 11 FDU(P).
The U.S. and UK forces use these official definitions for mission descriptors:
A new English translation of the book Twenty Thousand Leagues Under the Sea uses the word "frogman" uniformly and wrongly to mean a diver in standard diving dress or similar, to translate French scaphandrier.
Ancient Assyrian stone carvings show images which some have supposed to be frogmen with crude breathing sets. However, the "breathing set" was merely a goatskin float used to cross a river, and its "breathing tube" was to inflate it by mouth. See timeline of underwater technology.
Many comics have depicted combat frogmen and other covert divers using two-cylinder twin-hose open-circuit aqualungs. All real covert frogmen use rebreathers because the stream of bubbles from an open-circuit set would give away the diver's position.
Many aqualungs have been anachronistically depicted in comics in stories set during World War II, when in reality at that time period aqualungs were unknown outside Jacques-Yves Cousteau and his close associates in Toulon in south France. Some aqualungs were smuggled out of occupied France during the war (these may have been Commeinhes aqualungs), but the aqualung for the most part was not a player in combat in World War II.
The movie The Frogmen also made this mistake, using three- cylindered aqualungs, as in this image of a movie poster. DESCO were making three-cylinder constant flow sets that lacked the demand valve of the aqualung, but they were rarely deployed in the war, and the preferred system was the rebreather developed by Dr. Christian J. Lambertsen.
Ian Edward Fraser V.C. in 1957 wrote a book Frogman V.C. about his experiences. Whoever designed its dust cover depicted on it a frogman placing a limpet mine on a ship, wearing a breathing set with twin over-the-shoulder wide breathing tubes emitting bubbles from behind his neck, presumably drawn after an old-type aqualung. [2] [3].
There have been thousands of drawings (mostly in comics, some elsewhere) of combat frogmen and other scuba divers with two-cylinder twin-hose aqualungs shown wrongly with one wide breathing tube coming straight out of each cylinder top with no regulator, far more than of twin-hose aqualungs drawn correctly with a regulator, or of combat frogmen with rebreathers. See this image for the correct layout of an old-type aqualung.
This recent painting or CGI-type image on a website advertising the CSDS-85 frogman-detector sonar shows (bottom left corner) a frogman using open-circuit scuba complete with bubbles carrying a flying-saucer-shaped object which is likely meant to be a limpet mine.
Frogman-type operations have featured in many comics, books, and movies. Some try to reconstruct real events; others are completely fictional. Some make mistakes as described above. Examples are:
In ancient Roman and Greek times, etc, there were many instances of men swimming or diving for combat, but they always had to hold their breath, and had no diving equipment, except sometimes a hollow plant stem used as a snorkel. See the first part of the page at this link (in Portuguese).
The first known frogmen-type operations using breathing apparatus were by the Italian Decima Flottiglia MAS, which formed in 1938 and was in action first in 1940. See Timeline of underwater technology and each of the nations' frogman unit links below.
Italy started World War II with a commando frogman force already trained. Britain, Germany, the United States, and the Soviet Union started commando frogman forces during World War II.