Officially known as the Indian Marine Special Force, the unit was raised in 1987 out of the naval divers to lead amphibious operations. The personnel volunteering for the force have to undergo a rigorous two-year training, by the end of which only 10-25 percent of the enrolled commandos remain.

Marcos have been active in Jammu and Kashmir as part of the army's counter-terrorist efforts. Their main task is to control the infiltration of terrorists from across the border into Jammu and Kashmir through Jhelum river and Wullar Lake.

Some Marcos personnel are also attached to the army special forces units conducting counter-terrorism operations in the area.

'They operate similar to the Israeli Mistaravim units sporting beards and wearing 'pheren' (Kashmiri suit), thus making them indistinguishable from the locals,' another navy official added.

The Marcos have gained a fearsome reputation among terrorists who refer to them as the Dadhiwali Fauj (bearded army) since Marcos are the only non-Sikh personnel allowed to grow beards, or 'Jal Murgi' (water hens) for the speed in which they assault from the water and even 'Magarmachh' (crocodiles) for their amphibious capability.