In order to repel attacks on the coast and in coastal sea areas, the co-operation of all defence branches is required. The defence is largely based on marine obstacles and the concentrated fire of the Coastal Artillery, Navy and Air Force.

The effective range of Finland's fixed Coastal Artillery is not enough to repel distant attacks from the sea, but in order to maintain a credible defence, Finland must be able to take defensive action as soon as foreign vessels enter Finnish territorial waters. This can only be done with modern naval defence missiles.

Naval defence missiles (MtO-85) launched from the coast can be fired from a platform on the SISU transport vehicle.