DARPA's new unmanned sub-hunter - the Anti-Submarine Warfare Continuous Trail Unmanned Vessel (ACTUV) - unconstrained by the necessity of human operators, was commissioned in Portland today and will be sent to San Diego in a few weeks for a two-year-long trial period to test the concept.

Although DARPA will conduct the initial trials, the vessel will be turned over the Office of Naval Research (ONR) later this year, with the total test phase running through September 2018.

Unmanned surface and underwater vehicles have been in use for decades, but the development of the new ACTUV, also referred to as Sea Hunter, is being created with the goal of searching for submarines at sea for up to three months at a time.

The ACTUV is 130 feet long and can be remote-controlled and operated safely in all weather conditions. The lack of a crew means it can support manned ships during dangerous missions that would otherwise have potentially fatal results, such as countermining and submarine tracking.

Sea Hunter was launched in January and has been running trials in the Portland area. The San Diego trials will be the most extensive yet - two years long - and will not only test the concept of the ACTUV but also the various sensors that can be installed onto the displacement vessel.

The composite-construction design of the unmanned sub-hunter resembles a Polynesian war canoe, possessing a long, slim hull that is supported by Amas - outboard pontoons - that are connected to the vehicle by outriggers.

Sea Hunter will not be loaded with weapons, instead detecting and tracking submarines, and it will likely become an extension of Little Combat Ships, aiding them in their travels.

"We don't want ACTUV to be a one-trick pony," said Scott Littlefield, the project's program manager. "We really want to build a truck that's versatile to carry lots of different kinds of payloads."

The project is not a prototype for an operational Navy platform, but it could be in the future with additional research and development. As of now, it is fairly pricey, much more than a potential follow-on vessel.

"It looks we're going to deliver the first one for a construction cost of between $22 million and $23 million dollars," Littlefield said. "We're trying to get to a series cost of about $20 million a copy - not cheap, but not as expensive as a manned warship."

Daily operating costs are likely to be between $15,000 and $20,000, which do not include program costs such as development, design and software.