Abstract: An aluminum boat is provided including laterally outwardly bowed gunnels and each of the gunnels has an outer side tubular aluminum flotation member extending therealong, bowed to conform to and welded to the outer side surface of the gunnel. The opposite ends of each tubular flotation member are sealingly closed and the interior of the tubular member is occupied by non-liquid absorbing lightweight flotation material. The tubular flotation member is secured to the corresponding gunnel by first tack-welding one end of the tubular member to a generally straight rear portion of the gunnel and then yieldingly biasing the forward end of the tubular flotation member laterally inwardly while effecting localized heat to the tubular member in the area in which it diverges outwardly from the bowed portion of the gunnel to thereby reshape the tubular member to conform to the bowed area of the gunnel and enable the bent portion of the flotation member to be welded to the gunnel bowed portion.