Sub-drone sonar trap concept unveiled at Navy conference

Like a spring-loaded toy snake from a tube, the Sea Spear is intended to pop from a mother drone, expand to 50 times its length—and then hang around for months, silently listening for enemy submarines.The new sonar concept from dronemaker Anduril and Ultra Maritime, a Massachusetts-based company specializing in anti-submarine and electronic warfare, is meant to work with Anduril’s Dive XL or smaller Seabed Sentry underwater drones, drawing power from them and feeding its data to them