Plastic sailing boat hull with rigid bottom board - providing structural strength enabling hull to be thin

摘要

A sailing boat of plastics comprises an outer, ribless hull and an inner bottom board, attached to the inner face of the hull by a surrounding stringer flange and with foam filling between bottom board and hull. The bottom board is a principal structural member, accepting the major loads acting on the hull. It is preferably located approx. at the water line. In one variant, it is formed as a sandwich board, comprising two outer plates, and a foam centre. This bottom board may be either flat or slope slightly downwards away from the centre line towards the sides, in particular with a central stiffening upstanding bulge and with gutters or scuppers along both sides. By making the bottom board the principal structural member for the hull, it is possible for the outer shell of the hull to be made as a simple laminated sheet; thus the simplest form of construction is utilised in the part of the structure requiring the greatest curvature and care in manufacture, while the stronger member is incorporated as the relatively flat bottom board.