DARPA’s Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV) program seeks to develop a new type of unmanned surface vessel that could independently track adversaries’ ultra-quiet diesel-electric submarines over thousands of miles. One of the challenges that the ACTUV program is addressing is development of autonomous behaviors for complying with the International Regulations for Preventing Collisions at Sea, known as COLREGS. Substantial progress has been made in developing and implementing those behaviors. Currently, ACTUV’s system for sensing other vessels is based on radar, which provides a “90 percent solution” for detecting other ships. However, radar is less suitable for classification of the type of other vessels, for example determining whether the vessel is a powered vessel or a sailboat. Additionally, one of the requirements of COLREGS is to maintain “a proper lookout by sight and hearing.”
Nextbigfuture - This system will be the underwater equivalent of a Predator drone. There is no way you make a silent submarine drone for trailing enemy submarines criss-crossing the ocean without putting a torpedo or two into the system. The submarine hunter is in the DARPA project description, but the killer would come with the torpedo capability.