PURPOSE: To improve clearance effect for floating obstacle and prevention effect for side slip of a boat body by forming a scope-gate for removing of floating obstacle provided at a water suction port of the bottom of boat, into a slender lattice like one body provided with a pair of front and rear fitting parts and a pair of right and left flow regulating standing walls, out of synthetic resin.

CONSTITUTION: This scope-gate C fitted to the suction port 18 opened on the center part of the bottom of the body A of a jet propulsion small sized gliding boat, is injection-molded in one body which is formed into a slender lattice-like form and out of transparent synthetic material having high bending elastic modulus. Further, the scope-gate C is constituted out of a pair of front and rear fitting seats 21, 22 having a decided width (w) narrower than the opening width (s) of the suction port 18 and a pair of right and left parallel regulating flow standing walls 27, 28 bridged mutual fitting seats 21, 22. At turning of the body A, relatively acting pressing force of water is received with the standing side faces of the walls 27, 28, by bendingly deforming of them in the right and left direction, water is not dammed up and smoothly sucked in.