HONOLULU -- The owner of the Sheraton-Waikiki said it is moving ahead with plans to build rock groins and a new beach next to the hotel despite claims by some surf groups that said the project is too big and too risky.

The hotel's owners said they have scientific proof their plan will work.

Old-timers who hang out in the area said there never was much of a beach where the Sheraton stands now. Now there is nearly no beach at all. Sheraton owner Kyoya wants to change that.

Kyoya unveiled plans to spend $4 million for three T-topped groins to create an acre of new beach.

"We believe this will be a benefit for residents and visitors alike," said Ernest Nishizaki of Kyoya.

The 75-foot wide beach would be open to the public.

The groins would go from a seawall out about 180 feet.

Critic George Downing, founder of Save Our Surf, said the stone structures are so massive they could impact surf breaks further offshore.

"They don't know it's a crap shoot," Downing said.

Kyoya's engineers used computer simulation of wave patterns and said the stacked rock T-groins disrupt surf less than the existing seawall.

"There have been projects built using these same techniques that have been very successful," Nishizaki said.

If the structures work as planned, Downing fears they will multiply.

"It will destroy the beauty of Waikiki Beach, and this is just the beginning," he said.

Tourists had mixed feelings. One asked why another beach?

"You got great beaches -- lots of 'em. They're everywhere. It's perfect!" Vancouver resident Reine Mihtla said.

"I think it's a nice idea for the tourists. I just want to make sure it doesn't hurt the ecosystem at all," Los Angeles resident Lisa Efron said.

Kyoya said it is doing an environmental impact statement and seeking permits from a half-dozen government agencies.