Spitfire-Tunnel fin for the 12-9 Makaha

The fins are shown here with the main Spitfire cutaway fin sitting in its slot and the tunnel fin placed in position, it will actually be a bout 3/8ths of an inch lower once set in to the board.There are 73 pieces of paulownia in the tunnel fin, which is a two layer lamination with a wool/polyester blend cloth in between the laminations. The fin is glassed on the outside with bamboo cloth and the inside is resin coated.Six laminations of paulownia are used in the main spitfire fin, with 36 pieces in total. This cutaway fin has developed from the original spitfire fin to the point where it is hardly recognisable as a spitfire fin, but we still use the name as it is an upright planform fin using ellipitical leading and trailing edges.