While the U.S. Air Force's drones have been firing all sorts of air-to-surface missiles and bombs for roughly a decade now, the Navy took a big step toward getting in on the action last Friday when it launched six Israeli-made Spike missiles from an unmanned 36-foot motorboat.

The Navy pretty much admits that the project -- called the unmanned surface vehicle precision engagement module (USV PEM) -- is aimed at defeating threats that are straight out of Iran's war plans for the Persian Gulf region.

"The USV PEM project was developed in response to recent world events which have increased the concern over swarms of small attack craft, as well as threat assessments outlined in recent studies conducted by the Naval Warfare Development Command," said NAVSEA Naval Special Warfare Assistant Program Manager Mark Moses in a press release. "The study punctuates the effectiveness of these swarm attacks against both military re-supply ships and naval vessels. Technology demonstrated in this project can provide a capability to combat terrorists who use small low-cost vehicles as weapons platforms."

It sounds like the Navy is looking at using small fleets of these vehicles to patrol the waters around its larger vessels to shield against swarms of suicide attackers using tiny speedboats laden with explosives -- a longstanding vulnerability to U.S. ships designed to pummel large ships, aircraft, and inland targets from far away using missiles, torpedoes, and large caliber cannons.

How does USV PEM work? During last week's test, a crew in a control station on shore piloted the boat -- similar to the way UAVs are controlled -- and used its night vision and infrared cameras to find and kill targets using the missiles or a remotely controlled .50 caliber heavy machine gun that's mounted on board.  It's easy to imagine that in the future, these control stations could install aboard ships being protected by the USV PEM technology.

"During the demonstration, they engaged stationary and moving targets out to 3.5km," or just over two miles, says the Navy's press release.

The project is part of a joint-U.S.-Israeli collaboration run out of the U.S. Navy's sea systems command's Special Warfare Program Office. The same shop is responsible for, among other things, fielding a number of tiny submarines used to listen for enemy submarines, deliver Navy SEALS, and other secret squirrel activities.

Until the Navy can field these killer roboboats, it will be mounting remotely-controlled chain gunsaboard its ships and possibly lasers and Griffin missiles to defend against swarm attacks.