Abstract: A jet propulsion watercraft includes a controller configured or programmed to, when a docked state maintenance operation is performed to maintain a hull in a state docked at a pier, perform a docked state maintenance control to control a water flow generator to maintain generation of a jet of water from the water flow generator while controlling a water flow direction adjuster to maintain a direction of the jet of water generated from the water flow generator in a direction to cause the hull to be pressed against the pier.

Abstract: A jet propulsion system includes a jet propulsion mechanism located at a stern of a watercraft body and including a nozzle including a jetting port to eject a jet of water to generate a propulsive force, a nozzle actuator to rotate the nozzle to change an orientation of the jet of water, and a controller configured or programmed to perform an oscillation control to repeatedly oscillate the nozzle using the nozzle actuator when the watercraft body is launched.

Abstract: A jet propulsion system includes a jet propulsion mechanism including a nozzle, a steering actuator to rotate the nozzle in a right-left direction to change an orientation of a jet of water from a jetting port in the right-left direction, and a controller configured or programmed to, when a person has fallen overboard from a watercraft body, perform a turning control to point a stern toward the person who has fallen overboard by ejecting the jet of water from the nozzle and rotating the watercraft body using the steering actuator.

Abstract: A jet propulsion system includes a jet propulsion mechanism including a nozzle, a manual operator, a wireless controller, and a controller configured or programmed to, in a wireless watercraft maneuvering mode, perform a switching control to cancel the wireless watercraft maneuvering mode and forcibly switch to a manual watercraft maneuvering mode based on the manual operator being operated.

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: According to the present disclosure, a semiconductor apparatus comprises a semiconductor substrate including a drift layer of a first conduction type, a first base layer of the first conduction type and a second base layer of a second conduction type, a source layer of the first conduction type having higher impurity concentration than the first base layer, and a contact layer of the second conduction type having higher impurity concentration than the second base layer, a gate oxide film, a gate electrode, an interlayer insulating film provided on the semiconductor substrate and including a plurality of first contact holes that expose parts of the source layer and a plurality of second contact holes that expose parts of the contact layer, a source electrode, and a drain electrode. The first contact holes and the second contact holes are separated by the interlayer insulating film.

Abstract: A water jet propulsion boat includes a boat body and first and second sponsons on a first side of a rear portion of the boat body. A lower surface of the second sponson is higher than a lower surface of the first sponson, and a rear end of the second sponson is rearward of a rear end of the first sponson.

Abstract: A water jet propulsion boat includes a boat body including a keel, and a cavity in a front portion of the keel extending in a left-right direction of the boat body.

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 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.