Wikipedia
Marinejegerkommandoen (MJK) is the maritime/naval special warfare component of the Norwegian Special Operations Forces, established in 1953. It is one of two such Norwegian special operations forces, the other being the Forsvarets Spesialkommando, with the MJK being the older of the two units. The unit is headquartered on the Ramsund naval base in northern Norway, with other MJK operators stationed on the Haakonsvern naval base in southwestern Norway.
MJK is employed in the full spectrum of " frogman" operations, including swampland warfare, arctic warfare, special reconnaissance, recovery or protection of ships and oil installations, various counter-terrorism missions, hostage rescue and direct action.
To become a fully qualified MJK operator takes a minimum of two years and is further augmented by specialized courses during the following contract period, such as combat medic training, sniper training and forward air control (FAC) training.
As with any modern special operations forces, the training to become an MJK operator is long and arduous, both physically and mentally taxing. For example, during the selection phase (one of the final phases of MJK operator training), each of the candidates (which at this point of training consists of about 5-8 men out of an original 100-200) must carry a rucksack while being hunted by an "enemy force" consisting of Home Guard soldiers, military and law enforcement K-9 units and police officers. At some point during the test, the candidates are captured and must endure 36 hours of tactical questioning.
Foreign maritime/naval special operations forces comparable to the MJK in terms of training, missions, and tactics would be the United States Navy SEALs, South Korea's Navy Special Warfare Flotilla, the Brazilian Marine Corps' Batalhão de Operações Especiais de Fuzileiros Navais, and the Danish Frogman Corps (the Frømandskorpset), among others.