Just found this:In the mid-70s, Erle Pedersen from Cairns and Jick Mebane from Hawaii trade ideas while living at Whale Beach on Sydney's far northern beaches. Before moving south, Pedersen created the 'Kewarra Jet Bottom', devised to maximise energy out of the weak waves that broke at Kewarra Beach neach near Cairns. The Jet Bottom is a beautiful arrangement of curved channels, which, says Pedersen, "busts all forms of water tension."
Erle Pedersen with an early version of his Kewarra Jet BottomThe October 1975 issue of
Tracks runs a s**** article, 'U.S.O found in backyard' featuring a startled Terry Fitzgerald holding a futusristic surfboard. The Unidentified Surfing Object is one of Pedersen and Mebane's creations, while an accompanying photo shows four of their boards, one of them being a Kewarra Jet Bottom shaped in August 1975.The Jet Bottom is unlike all other channel bottoms yet it shares the same purpose: to influence water flow under the board and increase performance. Pedersen's contributions are significant and don't end here.and don't end here.
Tracks October 1975, an Erle Pedersen-shaped Kewarra Jet Bottom sits second from right, and Terry Fitzgerald holding an Unidentified Surfing Object.