Image Number 8 for United States Patent #6457433.
The present invention permits the positioning and support of a fuel tank in a stable state while preventing unnecessary stresses from being generated in the fuel tank. A tapered, single projecting portion for positioning is formed on either the bottom portion of an inner wall of a hull or the bottom of the fuel tank. A tapered, single depressed portion for positioning is fitted on the projecting portion, and is formed on the opposing bottom portion of the fuel tank or the inner wall of the hull, respectively. A space is formed between a peripheral wall of the fuel tank and the inner wall of the hull that permits contraction and expansion of the fuel tank.