Cruise ships and sonic weapons

A little-commented-upon aspect of the failed attack on a cruise ship off the coast of Somalia was that the pirates were driven away, at least in part, by an advanced, nonlethal, sonic weapon similar to the ones now being deployed in Iraq. The whole story is in The Sunday Times of Britain. The key paragraphs:

The Seabourn Spirit, owned by the cruise giant Carnival, was on its way from Alexandria in Egypt to the Kenyan port of Mombasa. It offers the height of luxury, with huge suites, marble bathrooms and more than one crew member to each passenger. Cruises aboard the liner cost from £6,100 for a 16-day sail to £18,270 for an epic 46-day voyage.

The liner used a sonic blaster to foil the pirates. Developed by American forces to deter small boats from attacking warships, the non-lethal weapon sends out high-powered air vibrations that blow assailants off their feet. The equipment, about the size of a satellite dish, is rigged to the side of the ship.

I don't remember seeing anything like that the last time my wife and I took a cruise, but then again we weren't on a luxury ship off the coast of Somalia.