MUSCAT, Oman — At this port north of the pirate-infested Gulf of Aden, passengers from the cruise ship M/S Nautica told The Associated Press on Wednesday they had been warned of the danger of a pirate attack even before they embarked, and that the crew used a device that blasted painful high-decibel sound waves to keep marauders at bay Sunday.

The attack on the nearly 600-foot-long cruise ship in the dangerous waters between Yemen and Somalia was the latest sign that pirates have grown more brazen, viewing almost any vessel as a target — even a large luxury liner with hundreds of tourists onboard.

But the assault on the Nautica lasted only five minutes, and the ship with about 650 passengers and 400 crew members sped away quickly and was not seized.

“We didn’t think they would be cheeky enough to attack a cruise ship,” said Wendy Armitage, of Wellington, New Zealand, shortly after disembarking for a daylong port stop in the Omani capital of Muscat.

During the assault, pirates on one of two skiffs fired eight rifle shots at the ship, according to its American operator, Oceania Cruises, Inc. The captain ordered the passengers inside and accelerated the ship, leaving the pirates far behind in their 20- to 30-foot wooden speedboats, powered with twin outboard motors.

Passengers reassured

Lynne Pincini, of Australia, said she was heading to a friend’s cabin when the order came to keep their heads down and stay inside. “We heard the announcement, and of course we went straight out on the balcony to have a look,” she said. “It was like a very large speedboat. It was running alongside the boat.”

The passengers were on a monthlong cruise from Rome to Singapore, a route that took them through the Gulf of Aden between Somalia and Yemen, where pirates have hijacked dozens of vessels this year.

At the beginning of the journey, the Nautica’s captain briefed the passengers on what the vessel could do to ward off pirates.

Alicia Moorehead said they were told the Nautica could outrun pirates and was equipped with high-pressure water hoses and a device that blasts painful sound waves at any bandits. Such devices can emit sounds up to 150 decibels — well above the normal pain threshold of 120 decibels — focused on targets several hundred yards away.

“We had been reassured that they had these ghetto blasters that could go through them. And we could outrun anything that they had,” Pincini said.

Moorehead’s husband, Pat, said the crew laid out the water hoses before the vessel entered the Gulf of Aden. “They had laid out the fire hoses for a high pressure repellent. They never did fire them up, but they were ready for them,” said Moorehead, a native of Long Beach, Calif.

“I will say the crew was very calm. They had prepared for this. Every staff member has an assignment in case of an emergency, and every one of them did it calmly and quickly,” he added.

Oceania Cruises would not comment on details of the ship’s security other than to say the crew used “evasive maneuvers and took all prescribed precautions.”

Pirate expert’s view

Roger Middleton, author of a recent report on piracy for the London-based think tank Chatham House, said such non-lethal defenses are preferable to having armed guards onboard — but their effectiveness is limited. Earplugs can foil the sound device, for example.

The ship’s high speed and the difficulty of boarding such a large ship probably were the reasons the pirates were not successful, Middleton said.