Park rangers at the Glen Canyon National Recreation Area are alarmed at the number of injuries they've already seen at Lake Powell as a new water toy makes its debut on lakes across the nation this summer.

The Wego Kite Tube, manufactured by SportsStuff Inc., is the latest sporting product to offer boating enthusiasts an adrenaline rush. Kevin Schneider, management assistant at Glen Canyon, said park rangers are still relatively unfamiliar with kite tubes, but they've already seen what happens when riders lose control of them.

A speedboat tows a rider on a 10-foot-diameter inflatable tube, and the rider can glide in the air to heights of 10 to 60 feet, depending on the tow rope's length, Schneider said. When a rider falls from those heights, the results can be traumatic.

"This is the first summer we've seen kite tubes," he said. "But we've already had four significant accidents."

Just last weekend, two people suffered injuries in separate kite-tubing accidents. In the first and more severe incident, a 29-year-old man from St. George lost control of his kite tube June 2 and fell about 40 feet to the water's surface while moving at approximately 40 mph, Schneider said.

Park rangers arrived and found the man had suffered a broken neck. They placed him on a backboard to stabilize him before calling for an emergency helicopter from Page, Ariz. A helicopter ambulance flew the man to St. Mary's Hospital in Grand Junction, Colo. Two other members of the man's party reported they also "got banged around on the kite tube" earlier that day.

The next day, a 14-year-old girl from Houston fell about 15 feet and lost consciousness when she hit the lake surface. She was also airlifted to St. Mary's Hospital. Doctors released her from the hospital after finding she was not seriously injured, Schneider said.

Rangers airlifted two other individuals in April and May for kite-tube-related injuries that included a punctured lung, broken ribs, chest injuries and back injuries, Schneider said.

Mike Mayer, chief ranger for Glen Canyon, last week sent a safety alert regarding the accidents to nearly 400 parks across the nation. Mayer said the victims had been using the kite tubes as directed when the tubes suddenly lifted to dangerous heights, became unstable and plunged down to the water surface.

"Victims have reported coughing up blood, torn muscles, whiplash-type injuries, broken ribs, punctured lungs and cervical fractures," he wrote.