Seychelles ? Pirates who attacked a cruise ship off the coast of Somalia grinned as they aimed grenade-launchers and machine guns at the deck and staterooms, some passengers said Monday, recounting the ordeal after safely docking.

The ship escaped by shifting to high speed and changing course, and the cruise line said Monday the crew also used a sonic weapon, which blasts earsplitting noise in a directed beam, as it tried to ward off the attack.

The Seabourn Spirit had been bound for Kenya when it was attacked by pirates armed with grenade launchers and machine guns Saturday about 100 miles off Somalia’s lawless coast.

The sonic device that helped ward off the attack, known as a Long Range Acoustic Device, or LRAD, is a so-called “non-lethal weapon” developed for the military after the 2000 attack on the USS Cole in Yemen as a way to keep operators of small boats from approaching U.S. warships. Makers of the device compare its shrill tone to that of smoke detectors, only much louder.

The gunmen never got close enough to board the cruise ship, but one member of the 161-person crew was injured by shrapnel, according to the Miami-based Seabourn Cruise Line, a subsidiary of Carnival Corp.