MUSCAT, Oman (AP) -- Ordered to get inside and stay down, Oregon tourist Clyde Thornburg heard the pirates' rifle shots hit the side of the luxury cruise liner - "Pop! Pop! Pop!" - then felt the ship speed up to escape.
At this port north of the pirate-infested Gulf of Aden, passengers told The Associated Press on Wednesday they had been warned of the danger even before they embarked, and the crew used a device that blasted painful high-decibel sound waves to keep the marauders at bay.
The attack on the nearly 600-foot-long cruise ship in the dangerous waters between Yemen and Somalia was the latest evidence pirates have grown more brazen, viewing almost any vessel as a potential target - even a large luxury liner with hundreds of tourists on board.
But the assault on the M/S Nautica lasted only five minutes Sunday, 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 cruise liner quickly, leaving the pirates far behind in their 20- to 30-foot wooden speedboats, powered with twin outboard motors.
"I couldn't see them shooting, but I heard them hitting the ship, 'Pop! Pop! Pop!'" said Thornburg, of Bend, Ore. "It wasn't really scary because the captain announced for the safety of everybody to get inside and get down, and by that time he was pouring on the coals to the ship and was outrunning them."
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.
Cargo ships, cruise liners and other vessels use the route - the only access to the Suez Canal shortcut between East and West - unless they are willing to add weeks to the trip by traveling around the southern tip of Africa.
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 repellant. 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.
Some passengers said the crew used the long-range acoustic device to ward off the attack, and at least two passengers described hearing two booms after the pirates fired their rifles.
Oceania Cruises would not comment on specific details of the ship's security other than to say the ship's captain and crew used "evasive maneuvers and took all prescribed precautions."
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 on board - 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.
"Lots of pirate attacks fail ... They will go for anything and keep trying until they get on board," he said. "I think they see these things as how much money they get out of them. And lots of Western tourists is very valuable."
International warships patrol the Gulf of Aden and have created a security corridor under a U.S.-led initiative, but attacks on shipping have not abated.
In about 100 attacks off the Somali coast this year, 40 vessels have been seized. Thirteen remain in the hands of pirates, including a Saudi supertanker filled with $100 million worth of crude and a Ukrainian ship loaded with 33 battle tanks.
Large ransoms are usually paid for the release of hijacked vessels, but a Somali official maintained Wednesday that a Yemeni cargo ship and its eight crew members were freed without a ransom after an appeal by local clan elders and regional officials.
The ship, released Tuesday, was seized last month in the Arabian Sea. A Yemeni security official had said the pirates were demanding a $2 million ransom.