PURPOSE: To facilitate the crew's operations on the deck and enable water to easily drain away, by making the height of a gunwale from the deck approximately constant longitudinally, providing scupper on both sides of the deck, with bending points in the intermediate parts between the low and the stern, and forming said conduits so that the depth thereof becomes maximum at said bending points.

CONSTITUTION: The heights A, B and C of the upper surface 50 of a gunwale 5 from a deck 2 are made approximately constant longitudinally. Moreover, scupper 4 which are provided on both sides of the deck 2 are provided with bending points in the intermediate parts between the low and the stern and formed so that the scupper conduit depth becomes maximum at said bending points, and scuppers 9 are provided. Thereby, in either of the cases of waterlines 7 and 8 corresponding to the rear load of the craft and the front load thereof respectively, the scuppers 9 at the bending points are located at the lowerest position, so that water is smoothly drained. In addition, because the height of the deck is not made high from the water surface, there is no interference with the net hauling-in operation or the like, and the longitudinal strength of the hull is not weakened.