Their main attributions include tasks such as reconnaissance, sabotage, hostage rescue and the elimination of targets of strategic value in maritime and riverine environments.

For enlisted (corporals or male sergeants with less than 30 years of age and able to reenlist), there is a C-ESP-MEC - Combat Divers Special Course, whose requirements for admission are the same as CAMECO.

The duration is 45 weeks of instructional activities also drawn as to the officers, but those who endure the enormous physical and mental pressure of the course will be adequately prepared for the specialized tasks assigned to MECS.

One of the last tests for GRUMEC candidates involves a 16 km swim, to be taken in pairs and using sidestroke, from Ilha Grande to Angra dos Reis.

Domestically, the group often takes part in training exercises that involve boarding vessels and oil platforms, as well as riverine operations in the Pantanal and Amazon.

[1] Since 2021, combat divers aboard ships such as Independência, União and Liberal were also tasked with training Navy and Coast Guard personnel from partner nations such as Equatorial Guinea, Ivory Coast, São Tomé e Príncipe, Cameroon, Nigeria and Cape Verde in the Gulf of Guinea as part of Brazil's effort against piracy in the region.