PURPOSE: To obtain a fishing boat and a boat for leisure-time amusement which are inexpensive and can speed up, by performing blow molding by making use of a molding material such as a polyolefin materials or ABS.

CONSTITUTION: The title boat possesses an expanded ejected part 2 on the upper fringe, a space between the outer wall surface 5 and inner wall surface 4 confronting with each other is provided with a hollow part 6 extending over the space between the whole wall surfaces, a plurality of a longitudinal and lateral grooves 7, 8 provided on the base are arranged on the inner wall 4, and the one longitudinal groove 7a is arranged on the outer wall surface 5. The longitudinal grooves 7, 7a possess facing welded part 15 between the inner and outer walls 4, 5, a reinforcing rib of a boat body 1 is formed by arranging a plurality of the longitudinal grooves 7, 7a and lateral grooves 8, and an insert metal fitting 3 constituted of stainless steel is buried in the outer wall of the base. Stepped recessed parts 14 and hole parts 9 are arranged on both sides of the insert metal fitting 3, the insert metal fitting 3 is buried in a blow molding mold on the basis of the hole part, and the insert metal fitting 3 is buried in the base of a boat with the same with a parison. A boat can perform speedup, and even if it is capsized it can be surfaced on the sea, since the boat body 1 is molded of a polyolefin material through blow molding, and is not corroded by sea water, requires no painting and possesses a light hull and smooth surface.