NATO has tested a series of alliance-made underwater sensors, meant to protect critical infrastructure in the oceans, by sending divers and drones to sneak past them. Several companies provided a mix of sensors for the drill designed detect a variety of signals in the acoustic, magnetic, passive, and electric realms. Exercise organizers hooked up the readings to an augmented reality simulator in order to have analysts experience it directly. The rapid proliferation of manned and unmanned underwater systems as well as the higher level of maritime activity have changed the operational landscape at sea, raising the intensity of competition over ocean spaces and introducing new types of threats. Are NATO drills necessary ?

