VANCOUVER, British Columbia (Reuters) - It may not be everyone's idea of the perfect vacation, but six hardy souls have coughed up $100,000 to spend the holiday season skiing at the South Pole.

The Vancouver travel firm that organized the trip says that for their money the six tourists got a tree and trimmings on Christmas Day, 24 hours of sunlight daily and a place in history.Adventure Network International Inc. describes the trip as the "ultimate adventure" and one that will give the participants exclusive bragging rights about their seven-week Antarctic summer vacation.

"It's a one-off deal, it's certainly the only time that we'll offer the trip," said Adventure Network general manager Hugh Culver, who helped organize the 50-day trek on behalf of Mountain Travel, a San Francisco area travel firm.

"As far as I know, it's the most expensive adventure travel trip ever sold."

Culver said the six tourists, two of them women, include a 24-year-old Harvard divinity student, a 56-year-old Michigan realtor and a 46-year-old Indian Army colonel.

They are being guided along the 740-mile route - in temperatures that can drop to minus 40 degrees, with winds of up to 40 knots - by a five-man team of polar experts.

After flying from the south coast of Chile Nov. 25, the 11 left Antarctica's north coast Nov. 27 and are expected to reach the pole as scheduled Jan. 15.

Culver told Reuters the tourists would spend the holdays on the polar icecap and dine in a specially constructed, 21-foot-long tent that could be erected in three minutes.

"They're real overachievers, they're very aggressive people, but at home they lead quiet lives," he said of the adventurers.

Culver said the six are being charged $70,000 for the South Pole trek itself. Earlier this year, they each had to take two weeklong training sessions in the Yukon and in Washingon State at a cost of $30,000 apiece.

Why is it such an expensive vacation?

"You're dealing with unbelievable costs and huge uncertainties," Culver said. "When you are flying down there, you never know what your costs are going to be because of weather conditions. A flight that normally takes us 18 hours to do may take seven days."

Only three other groups, totaling 13 men, have ever skied to the South Pole. Roald Amundsen lead an expedition that reached the pole Dec. 14, 1911; Robert Scott got there Jan. 17, 1912, and Britons Robert Swan and Roger Meare, with Canadian Gareth Wood, arrived in 1986.