The catamaran hull is built in a fibre-reinforced plastic sandwich of very low magnetic signature.

[3] Two large fans located on each side create an air cushion between the two hulls and a front and aft rubber skirt, lifting the vessel, giving small drag and a high cruise speed, as well as low susceptibility to the shock of exploding mines since only a small portion of the hull is actually exposed in the water.

Propulsion by water jet, again one in each hull, gives a low acoustic signature.

A degaussing system gives the vessels extremely low electromagnetic signature.

Alta was scrapped along with the Oksøy class M341 Karmøy prior to 23 July 2022