Abstract: A sponson device attachable to a watercraft body of a jet propelled watercraft includes a bow sponson located forward of a center of gravity of the jet propelled watercraft. The bow sponson protrudes from the watercraft body in a right-and-left direction, and is movable to a first position and a second position to adjust a trim of the watercraft body during turning of the jet propelled watercraft.

Abstract: A method for manufacturing a silicon carbide semiconductor device according to the technology disclosed in the present specification includes: forming a drift layer on an upper surface of a silicon carbide semiconductor substrate; forming a hard mask on the upper surface of the drift layer by anisotropic etching; and forming a first ion-implanted region in a surface layer of the drift layer by implanting ions into the drift layer in a state in which the hard mask is formed, in which the hard mask includes a sidewall perpendicular to the upper surface of the drift layer.

Abstract: A watercraft includes a hull, a wave detector to detect wave conditions on a water surface, a trim adjuster to adjust a trim angle of the watercraft, and a controller. The controller is configured or programmed to determine, based on a detection value of the wave detector, whether or not the water surface is smooth and, if it is determined that the water surface is not smooth, control the trim adjuster to increase the trim angle.

Abstract: A water jet propulsion boat includes a main chamber rib dividing the inside of an oil pan into a main chamber where an oil suction port of an oil suction tube is arranged, and an auxiliary chamber outside of the main chamber. The main chamber rib covers the oil suction port at least from the front side and from the left and right sides of the oil suction port. The main chamber rib projects upward from the floor of the oil pan. An opening through which oil passes is provided in the main chamber rib only rearward of a rear edge of the oil suction port. The main chamber and the auxiliary chamber communicate with each other through the opening.

Abstract: A water jet propulsion boat includes a main chamber rib dividing the inside of an oil pan into a main chamber where an oil suction port of an oil suction tube is arranged, and an auxiliary chamber outside of the main chamber. The main chamber rib covers the oil suction port at least from the front side and from the left and right sides of the oil suction port. The main chamber rib projects upward from the floor of the oil pan. An opening through which oil passes is provided in the main chamber rib only rearward of a rear edge of the oil suction port. The main chamber and the auxiliary chamber communicate with each other through the opening.