They were never built to stare at the sky. Fleet submarines were hunters, creatures of the deep that stalked their prey in silence. Yet, in the uneasy years after the Second World War, the U.S. Navy found itself short on eyes. The kamikaze had taught a brutal lesson—that fleets needed early warning, and surface radar picket ships were sitting ducks. The answer, paradoxically, was to turn the predators of the deep into guardians of the air.