DARPA just released some neat but brief 360-view footage of their Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV) including some of it underway at a good clip (27 knots). The 132-foot USV is meant to be the expendable subchaser of the 21st century, and actually looks pretty sweet.
If they can get past concept and put 50-100 of these cheaply in the Western Pac, networked all sweet to a central ASW War Room, it could really negate all the skrilla the Norks and PLAN are dropping on subs.