The Combat Divers Group (Portuguese: Grupamento de Mergulhadores de Combate), abbreviated to GRUMEC, is a special forces unit of the Brazilian Navy.
The GRUMEC was created in 1974 and is subordinate to the Submarine Force, which provides the primary means of transport for combat diver missions. GRUMEC teams can be transported to the target by a submarine, from which can reach the target by swimming, in kayaks, or in inflatable boats that can be launched from the submarine while it is still under water. The GRUMEC can also reach the target by parachute or helicopter.
The function of the GRUMEC is to infiltrate undetected in coastal and riverine environments in order to perform tasks such as reconnaissance, sabotage and the elimination of targets of strategic value. In this sense it is similar to the U.S. Navy SEALs and British Special Boat Service.
A member of the force is known as a "MEC", which is an abbreviation of "mergulhador de combate", meaning "combat diver".
See more in: https://en.wikipedia.org/wiki/GRUMEC