A tourist yacht and its crew of seven was hijacked by Somali pirates near the Seychelles islands off Africa's east coast Wednesday, said the director of the British agency that books diving tours on the luxury yacht.

The Indian Ocean Explorer had just dropped off its contingent of tourists before it was seized, said Kirk Green, director of Aquatours, a London-based tour operator.

Green said the British Navy e-mailed him to tell him the boat had been hijacked and would be taken to Harardhere, a pirate stronghold north of Mogadishu. Green said he was told by the navy to expect the ship to be held about three months.

"It's the first time it's happened to us, so it's a bit of a shock at the moment," he said. "Obviously one of the feelings we have is relief because none of our clients were taken. But on the other hand, we are extremely concerned about our crew."

All seven crew members are from the Seychelles, he said.

Green said he did not know the boat's exact location when it was seized or where it was headed when it was taken.

Diving, fishing and sightseeing tours on the seven-bedroom boat start at $3,000, and the majority of customers are British, he said. The ship can carry 14 passengers along with crew.

"This is not a boat that transports crews around the world and is worth huge amounts of money," he said. "This boat operates really for the love of it, and if we manage to break even at the end of the day, we're really lucky."

Green said the converted oceanographic research ship, which is registered in Panama, was recently Swiss-owned. The boat was recently resold, and he could not confirm the identity or nationality of the new owners.

Piracy is rampant off the coast of Somalia, which has not had a functioning government for 18 years. In the last year alone, pirates have captured trawlers, small fishing boats, cruise ships and even a cargo ship laden with heavy weapons. Last week, pirates attacked a German military supply ship, which returned fire, pursued the seven pirates and then detained them with help of other ships participating in the anti-piracy mission off the Horn of Africa.

Despite such recent successes, piracy is still big business. Pirates have made off with up to $80 million in ransom in the past year, seizing 42 vessels off the country's 1,900-mile coastline along the Horn of Africa.

"I don't understand why the countries involved don't just go down there and sort it out once and for all," Green said.

Somali pirates are common in the Gulf of Aden, through which 20,000 merchant ships a year pass on their way to and from the Suez Canal. But analysts say an increase in foreign warships patrolling the area has forced pirates to shift their operations east into the Indian Ocean, toward the Seychelles.