BARRYTOWN (AFP) - Sporting a top hat, his eyes twinkling with excitement, Brett Kolfrat surveys a wide stretch of New York's frozen Hudson River.

The extremely cold winter in the northeastern United States has been miserable for many, but not for Kolfrat. Thanks to the deep freeze, he just took his elegant 1908 ice boat out for a spin.

"I lived my whole life for this event," says the 52-year-old electrician as he caresses the mast of the Genevieve -- effectively a sailboat made of a wooden backbone with a platform at the rear -- mounted on heavy cast-iron blades.

"We work so hard with our ice boats trying to get on and off the ice all these years," Kolfrat said. "For all of us to be here this year, it's a once-in-a-lifetime thing, that's what we live for."

Kolfrat is part of a crowd of American ice boat aficionados who have gathered near the historic hamlet of Barrytown, about a two-hour drive north of Manhattan, since word spread in late February that this year's bitterly cold winter seemed to have paid off -- at least for them.

The severe winter weather created a massive 30-kilometre stretch of perfectly smooth ice that is at least 30 centimeters thick, according to some estimates.

Kolfrat's boat was one of about two dozen that took to the ice during the first two weekends of March, capitalizing on the perfect conditions.

'Nice sailing'

The spectacle was more common in the late 1800s and early 1900s, when ice boating was a pursuit of well-heeled families such as that of U.S. president Franklin D. Roosevelt -- and when temperatures were generally colder.

Now, the river is only frozen solid every so often.

Kevin Lawrence, a 31-year-old fruit farmer, says his family has been ice sailing for generations. His grandfather was one of the forerunners who brought the pastime back to the river in the 1970s.

Out on the ice, Lawrence -- his hand firmly on the rope controlling the mainsail -- changes tack, speeding towards the opposite shore, which is part of the neighboring state of New Jersey.

"Today, we've got hard ice, and we'd like a little bit more wind, but we're getting nice sailing," he says.

The last time 78-year-old John Vargo took out the star of the show, the Jack Frost, was in February 2003.

The vessel, which belongs to the Hudson River Ice Yacht Club, has navigated the river only a handful of times since then.

The boat, which in the 1800s sped past trains departing from New York and was restored in 1973, can travel at up to 75 miles per hour.

But -- in the absence of appropriately cold weather -- it has spent most winters under wraps at the Lawrence family's apple farm.

It's 'rare, very rare'

A thrilled crowd of spectators -- and even a brass band -- watched the boats' grand return to the ice.

In the distance, a freighter sounds its foghorn. A dozen wooden ice boats rush to the giant red and blue vessel, some 20 times their size, as it attempts to force passage through a narrow channel cut by U.S. Coast Guards.

Frank Wall, the captain of the Aurora, a 30-foot ice yacht from the turn of the last century, greets the freighter's captain, whom he knows.

"This is rare, very rare... I get emotional," says Vargo, watching them, his head wrapped in a custom-made, coyote fur hat.

Vargo -- the publisher of Boating on the Hudson magazine -- is convinced that this will be his last chance to go ice yachting on the Hudson. He predicts the conditions might not be right for another 30 years.

Indeed, temperatures in the New York area are on the rise.

Kolfrat regrets that he has no coat or tails to accompany his top hat. The boats' captains in the past "were all billionaires. They were the richest men in the country," he says.

"We're all laborers -- we're construction workers, teachers, farmers."

Not billionaires, he adds, "but passionate."