After starting a discussion about the turbo tunnel fin in the Aussie windsurfing forum Seabreeze some people posted shots of these fins. The tubed windsurfing fins and split fins are taken from finmaker Deboichet's website. I don't know the provenance of the unusual wooden surfboard setup. Meanwhile discussions about the turbo fin seem to conclude that the fin is good on longboards for noseriding, but creates way too much drag for windsurfing. So I'm thinking "what about putting one on a windsurfing board and sailing it fin first?" Bizzarro freestyle possibilities?