Sea Hunter has the capability to hunt stealthy foreign submarines -- China's and Russia's navies both have big submarine fleets -- and follow them for two to three months at a time. Deputy US Defense Secretary Robert Work clarified to Reuters during the event, though, that the drone doesn't have weapons. If the military decides equip it with any, Work said the decision to use them would be made by human personnel. We're guessing they'd be controlled remotely, since the ship wasn't designed to house a crew on board. The ship is slated to start its open-ocean tests this summer off the California coast.

DARPA next-generation unmanned surface vessel being christened this morning in Portland. pic.twitter.com/GW8nLszPJF — DARPA (@DARPA) April 7, 2016