An amphibious vehicle includes a vehicle body; a flap supported at a lower portion in a traveling direction of the vehicle body to be able to swing in a direction in which an upper edge portion approaches and separates from the vehicle body; a support column which has a fluid actuator capable of expanding and contracting in accordance with a pressure of a working fluid to a cylinder chamber, is connected to the flap in at least a first end portion in a longitudinal direction, and performs adjustment of a swinging angle of the flap by expansion and contraction of the fluid actuator; a power source which supplies the working fluid to the cylinder chamber; and a safety valve which communicates with the cylinder chamber, and opens when an internal pressure of the cylinder chamber becomes greater than a predetermined pressure to discharge the working fluid in the cylinder chamber.

An amphibious vehicle includes a vehicle body; a flap supported at a lower portion in a traveling direction of the vehicle body to be able to swing in a direction in which an upper edge portion approaches and separates from the vehicle body; a support column which has a fluid actuator capable of expanding and contracting in accordance with a pressure of a working fluid to a cylinder chamber, is connected to the flap in at least a first end portion in a longitudinal direction, and performs adjustment of a swinging angle of the flap by expansion and contraction of the fluid actuator; a power source which supplies the working fluid to the cylinder chamber; and a safety valve which communicates with the cylinder chamber, and opens when an internal pressure of the cylinder chamber becomes greater than a predetermined pressure to discharge the working fluid in the cylinder chamber.

A system is provided and includes a trim tab, a hinge assembly, an actuator, and a controller. The trim tab adjusts at least one of pitch, roll or yaw motion of a marine vessel while the trim tab is in a deployed state. The trim tab includes a member, which has first and second ends and curves outward between and forward of the first end and the second end in a direction away from a point rearward of the member. The hinge assembly attaches a rearmost end of the first trim tab to the marine vessel at a location rearward of the member. The member rotates about a portion of the hinge assembly. The actuator actuates the trim tab. The controller controls the actuator to transition the member of the trim tab between a retracted state and the deployed state to adjust an attitude or motion of the marine vessel.

A system is provided and includes a trim tab, a hinge assembly, an actuator, and a controller. The trim tab adjusts at least one of pitch, roll or yaw motion of a marine vessel while the trim tab is in a deployed state. The trim tab includes a member, which has first and second ends and curves outward between and forward of the first end and the second end in a direction away from a point rearward of the member. The hinge assembly attaches a rearmost end of the first trim tab to the marine vessel at a location rearward of the member. The member rotates about a portion of the hinge assembly. The actuator actuates the trim tab. The controller controls the actuator to transition the member of the trim tab between a retracted state and the deployed state to adjust an attitude or motion of the marine vessel.

A boat includes at least three trim devices positioned aft of the boat's transom. To improve the boat's ability to get on place, each trim device is initially positioned to a deployed position. The speed of the boat is then determined as the boat gains speed. When the speed of the boat exceeds a first predetermined threshold, the first trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a second predetermined threshold, the second trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a third predetermined threshold, the third trim device is moved from the deployed position to a non-deployed position. At least one of the first, second, and third predetermined thresholds is different from the other two of the first, second, and third predetermined thresholds.

A boat includes at least three trim devices positioned aft of the boat's transom. To improve the boat's ability to get on place, each trim device is initially positioned to a deployed position. The speed of the boat is then determined as the boat gains speed. When the speed of the boat exceeds a first predetermined threshold, the first trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a second predetermined threshold, the second trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a third predetermined threshold, the third trim device is moved from the deployed position to a non-deployed position. At least one of the first, second, and third predetermined thresholds is different from the other two of the first, second, and third predetermined thresholds.

An amphibious vehicle, which enables wave making resistance upon traveling on water to be reduced and propulsive performance of its vehicle main body to be improved, is to be provided. An amphibious vehicle of the present invention includes: a vehicle main body that is movable on water and on land; a rear portion flap having a front end portion fixed to a rear portion of the vehicle main body; and end plates respectively provided at both side end portions of the rear portion flap.

A boat includes at least three trim devices positioned aft of the boat's transom. To improve the boat's ability to get on place, each trim device is initially positioned to a deployed position. The speed of the boat is then determined as the boat gains speed. When the speed of the boat exceeds a first predetermined threshold, the first trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a second predetermined threshold, the second trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a third predetermined threshold, the third trim device is moved from the deployed position to a non-deployed position. At least one of the first, second, and third predetermined thresholds is different from the other two of the first, second, and third predetermined thresholds.

A boat includes at least three trim devices positioned aft of the boat's transom. To improve the boat's ability to get on place, each trim device is initially positioned to a deployed position. The speed of the boat is then determined as the boat gains speed. When the speed of the boat exceeds a first predetermined threshold, the first trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a second predetermined threshold, the second trim device is moved from the deployed position to a non-deployed position. When the speed of the boat exceeds a third predetermined threshold, the third trim device is moved from the deployed position to a non-deployed position. At least one of the first, second, and third predetermined thresholds is different from the other two of the first, second, and third predetermined thresholds.

A watercraft has a hull with a central portion which selectively raises from a lower position to a recessed position within a tunnel of the boat hull with a hydraulically controlled means. The hydraulically controlled means is disposed within the hull and adjacent the tunnel. A motor mount is in mechanical communication with the adjustable portion of the boat hull and raises or lowers correspondingly with the adjustable portion of the boat hull.