People seeking an adrenaline rush of 'JetLev' , the wild new water sport in Hawaii, might have to face some heat from protestors who have raised concerns over the possible safety and environmental threat the sport might cause.

'JetLev' can lift a person 30 feet in the air with the help of pumped water, making a person fly like George Jetson or Iron Man.

Fishermen, scientists and state officials are showing less enthusiasm to promote the water-powered jet packs in the Aloha state. They are questioning the safety of the device and are calling for greater regulations amid fears that it might harm the aquatic ecosystem in the state's busy tropical waters.

Flyboard, another type of this new adventurous water sport, which propels riders 45 feet in the air has also become very popular among tourists.

Water sport enthusiasts are rushing to beaches to try out this new ride, partly stirred by several promotional videos on YouTube that show riders shooting out of the ocean into the sky, then diving back in the water like dolphins.

The device has already garnered a lot of popularity in San Diego, Key West, Fla., and Cancun, Mexico.

Randy Awo, an enforcement officer at the Department of Land and Natural Resources, expressed concerns over its dangerous manoeuvres, such as riders dive-bombing into the water next to moving boats and the possibility of crashing into a reef.

Bob Richmond, a coral scientist at the University of Hawaii is worried about the effects of the device-generated sound on the fishes because they tend to avoid areas that are too loud.

Plus, Richmond said that this device could prove fatal as some of the fish and coral larvae could get sucked in the equipment and die.

"More and more and more these bays are being run over, taken over by other activities. The marine life that depend on these places - they're being displaced," said Carl Jellings, a fisherman.

William Aila, chairman of the Board of Land and Natural Resources, said that the state authorities might introduce this water sport in restricted areas.

"When you look at it, it looks fairly exciting," Aila said. "But you got to look beyond the excitement."