Head to Lido Beach on a windy evening, and look for a sinewy guy attached to a giant kite: Rob Hassle, king of the local kiteboarding scene. At 36, Hassle is at the vanguard of this latest extreme sport, in which thrill-seekers launch themselves across the waves on a board strapped to their feet, propelled by a kite attached to their waists.

A turquoise kite taut and soaring 100 feet above him, Hassle skims the surface of the waves until he's a spot on the horizon, then swoops around and leaps-doing one, two, three full flips until he gracefully descends on the tip of foamy whitecap like an airborne figure skater. Jumping is the key: It's while the kiteboarders are suspended in air that they perform the stunts and tricks that garner trophies and medals. "When you jump, it gets really quiet. You hear people talking on the beach and babies crying," Hassle says. "There's no gas motor; you sneak up on everything. It's all about catching air."

But the sport can also be extremely dangerous. Kite design has improved vastly over the past three years; the "foils," as they are known, are light enough to provide a fun ride in the limpest of winds, more stable than ever and can relaunch from the water. But they are also powerful enough to lift riders up to 40 feet in the air and keep them suspended for as much as 15 seconds.

"It will scare you to death, and it is physically and emotionally challenging," says Laurel Kaiser, a kiteboarding instructor and the owner of Island Style Windsurfing.

A licensed boat captain who always enjoyed windsurfing and wakeboarding, Hassle first saw a kiteboarder in action on late-night television in 1999, a couple of years after the sport had caught the imagination of Europeans. He did some online research and ordered a kite (they were manufactured mostly in France at the time) and started teaching himself. "Rob really pioneered this," says Kaiser. "Around here, he's the god of windsurfing."

Last year, Hassle placed first in the Eastern Surfing Association's championships in Virginia Beach and this year, he was eighth in international championships in Miami. Now he's training for the King of the Great Lakes title in Michigan and the King of the Air title in Maui.

Locally, Hassle hits the waves with a group of about 12 Sarasotans-ranging from an emergency room nurse and a chiropractor to a tool distributor and finance executive-who stay tuned to The Weather Channel and call each other the minute the wind picks up.

"This is an adrenaline rush; you're harnessing the wind," Hassle says. "It feels like flying."