PURPOSE: To provide a sea-going craft of excellent stability by providing a center body and curved wings extending outward from both sides of the body to the catamaran type hulls on right and left both ends, and providing hydrofoils extending downward on the center body and the right and left respective hulls.

CONSTITUTION: This craft is constituted of a center cabin or a body 16, and two curved wings 12, 14 outward extending from the body 16 up to respective catamaran type hulls. The trailing edge parts 20 of the respective wings 12, 14 are extended at an angle of advance, and spaces opening in the flight direction and meanwhile closing in the anti-flight direction are formed on the underside of these wings 12, 14. The body 16 and the right and left respective hulls 18 are provided with hydrofoils 77 respectively extending downward, and the respective hulls 18 house fuel tanks. Further this craft is provided with a propulsion device (not illustrated) such as rotary propeller construction on the wings 12, 14 and the like.