A small marine vessel includes a vessel body, a propulsion device, a propulsion device housing provided in a rear portion of the vessel body and that houses the propulsion device, a first cover that substantially covers and seals the propulsion device housing, and a second cover disposed above the first cover and that covers the first cover and an opening of the propulsion device housing.

A water propulsion electric powered water recreation surf board with an integrated water propulsion jet to provide additional thrust for maneuvers and different selectable thrust levels as needed during the maneuver. The water propulsion electric powered water recreation surf board includes a body having an upper surface and bottom surface and a water propulsion system integrated into the body including a water inlet on the bottom surface, and a water propulsion nozzle and propeller on the upper surface. An electric motor connects to rotate propeller for drawing water into the propulsion system and expels a pressurized column of water through the water propulsion nozzle. A removable rechargeable battery is connected with the electric motor and a controller with a user control pad on the top surface of the body to allow the user to control the operation of the water propulsion system.

A water propulsion electric powered water recreation surf board with an integrated water propulsion jet to provide additional thrust for maneuvers and different selectable thrust levels as needed during the maneuver. The water propulsion electric powered water recreation surf board includes a body having an upper surface and bottom surface and a water propulsion system integrated into the body including a water inlet on the bottom surface, and a water propulsion nozzle and propeller on the upper surface. An electric motor connects to rotate propeller for drawing water into the propulsion system and expels a pressurized column of water through the water propulsion nozzle. A removable rechargeable battery is connected with the electric motor and a controller with a user control pad on the top surface of the body to allow the user to control the operation of the water propulsion system.

There is provided a hull assembly for reducing water resistance on a ship hull and improving the manoeuvrability on said ship. The hull assembly is mountable on a pre-existing ship hull having a bow, and a stern. The hull assembly comprises a propeller chamber for enclosing at least one propeller positioned proximate the stern of the ship hull, and a plurality of ducts attachable to an outer surface of the ship hull. The ducts extend in a longitudinal direction from a front part of the bow to the propeller chamber. The ducts have a plurality of bow openings along the bow for the water to flow directly toward the rear part of the stern, each of the ducts comprising at least one stern opening near the propeller chamber. The propeller chamber comprises two opposed chamber sides; at least one chamber opening on each of the two opposed chamber sides; and a rear opening for each of the at least one propeller.

A large-scale, high-mobility all-terrain vehicle is equipped with at least two articulated front legs and at least two articulated rear legs. Each articulated leg is connected to the vehicle structure about two mutually orthogonal axes to allow a variation of the track width distance between each pair of track assemblies and a variation of the height of the vehicle structure with respect to each track assembly. Each track assembly is connected to the respective leg about a horizontal transverse axis and about a vertical axis, and about a longitudinal axis. The vehicle structure has a front module and a rear module articulated about a longitudinal axis and a driving cabin that can be rotated downwards to allow ample visibility of the ground in front. The track assemblies are connected to the respective articulated legs by quick coupling devices.

A large-scale, high-mobility all-terrain vehicle is equipped with at least two articulated front legs and at least two articulated rear legs. Each articulated leg is connected to the vehicle structure about two mutually orthogonal axes to allow a variation of the track width distance between each pair of track assemblies and a variation of the height of the vehicle structure with respect to each track assembly. Each track assembly is connected to the respective leg about a horizontal transverse axis and about a vertical axis, and about a longitudinal axis. The vehicle structure has a front module and a rear module articulated about a longitudinal axis and a driving cabin that can be rotated downwards to allow ample visibility of the ground in front. The track assemblies are connected to the respective articulated legs by quick coupling devices.

An underwater propulsion unit including a propeller, a motor, and a housing. The motor is disposed further forward in a propulsion direction than the propeller and drives the propeller into rotation. The housing that accommodates the motor and the propeller includes a first portion and a second portion. In the second portion disposed further rearward in the propulsion direction than the first portion, an introduction inlet and a spout outlet are provided. The introduction inlet (21) introduces water into the housing, and water introduced from the introduction inlet and delivered by the propeller is spouted out of the housing. When viewed in a direction parallel to the propulsion direction, the introduction inlet is disposed further outward than the first portion and introduces water into the housing in a direction parallel to the axis of the propeller.

This amphibious vehicle is provided with a body (11), a traveling device (12) that causes the body (11) to travel on land, a sailing device (13) that causes the body (11) to sail on water, a front flap (31) of which the distal end is inclined upward and the proximal end is rotatably supported by a horizontal shaft (34) on the front end of the body (11), a hydraulic damper (32) serving as a damping member that damps displacement of the front flap (31) relative to the body (11), and a compression coil spring (33) serving as a restoring member that restores the position of the front flap (31) relative to the body (11).

A jet propulsion device includes an impeller housing, an impeller, a sleeve, a first ring-shaped elastic body, and a second ring-shaped elastic body. The first ring-shaped elastic body is disposed between the impeller housing and the sleeve, and is located between a first end and a middle of the sleeve in an axial direction of the sleeve. The second ring-shaped elastic body is disposed between the impeller housing and the sleeve, and is located between a second end and the middle of the sleeve in the axial direction of the sleeve.

A jet propulsion device includes an impeller housing, an impeller, a sleeve, a first ring-shaped elastic body, and a second ring-shaped elastic body. The first ring-shaped elastic body is disposed between the impeller housing and the sleeve, and is located between a first end and a middle of the sleeve in an axial direction of the sleeve. The second ring-shaped elastic body is disposed between the impeller housing and the sleeve, and is located between a second end and the middle of the sleeve in the axial direction of the sleeve.