Idle chat continues to circulate around town about renaming the America's Cup the Kiwi Cup in honor of all the New Zealanders in key roles on top teams. Well, not so fast.

It turns out the brainstorm behind the so-called Kiwi clip-on, the radical appendage that could seal another Cup win for Team New Zealand, came not from a Kiwi but from a stalwart ex-U.S. Navy officer, Clay Oliver of Annapolis.

Oliver, a naval architect and 1973 graduate of the Naval Academy, has been working as a designer for Team New Zealand since 1996 and was a member of the design group that drew up NZL 60, the black boat that successfully defended the Cup three years ago.

He had offers to move to other camps but chose to stay, and late in 2000 came up with the offbeat idea of attaching a horizontal appendage to the bottom of the next generation of race boats to increase waterline length, and thus speed.

Encouraged in his radical plan by design coordinator Tom Schnackenberg, Oliver persevered for two years on the underwater gadget they code-named "hula." The result is the revolutionary design unveiled Tuesday that has the Cup community buzzing.

Cup rules let teams attach non-moving appendages to the hull, but no one has ever made one as big as the stiff, 8- by 20-foot, surfboard-like flap that runs like a second skin from behind the keel all the way beyond the rudder on both NZL 81 and 82. The gimmick extends the working length of the boat when it heels, increasing theoretical top speed.

What gave him the idea?

Oliver said he was working on two big-boat designs two years ago -- one for the America's Cup and another for an unrestricted record-chaser, a 125-foot-plus sailboat called Mari-Cha commissioned by U.S. businessman Robert Miller. Mari-Cha's goal was to beat seagoing speed records, with no restrictions on design other than to be fast and seaworthy. Cup boats by contrast obey hundreds of pages of design rules. Bouncing back and forth between jobs, Oliver began to wonder how he could make the rule-bound Cup boat look more like the unrestricted Mari-Cha, with its low transom and powerful stern section.

He read and reread the rules and came up with the idea of tacking on the underwater appendage, which he relayed to the rest of the design team in a Dec. 11, 2000, e-mail. Schnackenberg was immediately intrigued.

Oliver, working closely with the team's model-testing expert, Andy Claughton, a Briton, and co-designer Mike Drummond, a Kiwi, drew up a quarter-scale model for testing and the quest was on. When the two new race boats were launched last year, both had the appendages on, but were hidden from rivals by elaborate security skirts that stayed on even as they were towed to and from testing waters on Hauraki Gulf.

The first glimpse anyone got was Tuesday, and it was an eye-opener. Rules experts from both surviving challenger camps, Swiss Alinghi and San Francisco-based Oracle/BMW, are scouring Cup regulations with an eye toward challenging the legality of the hula hulls. So far no protests have been filed.

No one knows how much extra speed the clip-on can produce, but Alinghi has been testing its own version for at least a few months and could make a stab at duplicating it if it advances to the Cup match Feb. 15. First, Alinghi must beat Oracle in best-of-nine challenger finals starting Saturday.

Oliver reckons a late attempt would come up lacking. He said both TNZ boats were designed specifically to incorporate the hula and have built-in advantages no add-on could match. He said by itself, the hula produces only modest speed gains, offset to a degree by the extra weight they bring to the hull package and the increased drag from water that gets between hula and hull. But in concert with other design advances, the edge can be significant, he said.

Does it mean a slam dunk for TNZ in next month's Cup match?

"We have no idea!" laughed Oliver, who commutes back and forth to Annapolis for visits with his wife and 14-year-old daughter Emily, who is in high school there. "But we're reasonably happy with where we stand."

Clay Oliver, left, and Mike Drummond join Team New Zealand chief Tom Schnackenberg, center, in front of NZL 82 during unveiling of boat appendage.