The Sail America Foundation and skipper Dennis Conner, in San Diego, have unveiled a prototype 12-meter race yacht built for the America's Cup challenge, but kept the boat's keel under wraps to shield design innovations.

Conner hopes the alterations will give him an edge in 1987, when the America's Cup challenge series is to begin off the coast of Perth, Australia.

Conner skippered the Liberty that was beaten by the technologically superior Australia II in the 1983 America's Cup race off Rhode Island.

Conner said he will leave Sept. 26 for Hawaii with the new boat, Stars and Stripes, and two others for testing from Oct. 15 through next July.

"In our research, we found that in Perth, Western Australia, the conditions (during) the America's Cup only exist for 2 1/2 months (when) the land heats up and it blows very hard," Conner said.

"Hawaii blows 22 days a month at the same velocity that the America's Cup will be raced in. By racing in Hawaii, we'll basically have 10 months of strong wind conditions similar to what the America's Cup will be held in and no one else will have more than 2 1/2 months."