All of these ships have been used for military intelligence purposes by the Norwegian Armed Forces, the first two entering service during the Cold War.

Her main role is surveillance of the Russian Northern fleet's activity in the Barents Sea, but is constructed for operations all over the world.

The ship was contracted in March 1991 from Aker Yards and was commissioned in 1995 after the technological development had made the former vessels no longer covered their role.

The shape of the hull is characteristic with a sharp bow, sinusoidal waterline, a descending rear body that ends in a straight cut-off stern where the ship has the largest width.

A little while later, an earthquake measuring device picked up a second explosion thought to have occurred when Kursk hit the seabed and 5–7 torpedo warheads detonated, estimated to be equal to two tons of TNT.

[10] The new ship, the fourth Marjata, was docked at the Naval Weapons Station on the York River in the United States for the summer of 2015.

Though the Marjata IV was supposed to replace her predecessor, FS Eger, they have been reported to have worked together on multiple missions.