PURPOSE: To heighten the rigidity of a fender and prevent it from dropping off, by providing a lip on the fender and placing the top of the fender below a gunwale to prevent a net from being hooked on the fender during the net casting work or the like.

CONSTITUTION: A gunwale 3 is provided on the top of the side plate 1 of a boat. To manufacture the gunwale 3, a fiber-reinforced plastic plate 31 shaped as an inverted J is bonded to the inside of the top 11 of the side plate 1 by fiber-reinforced plastic 13. The lower end of the gunwale 3 is secured by a sealing material 6. A fender 4 is mounted on the outside of the gunwale 3 by screws 40. The fender 4 has a lip 41 which is tightly fitted on the slope of the outer corner of the top of the gunwale 3 so that the fender is not protruded above the gunwale 3.