An energy efficient ship is achieved by powering the ship using at least one propulsion level, each propulsion level having large grids at the forward and stern ends of the ship and side channels incorporating turbines that move water through the ship, rather than around the ship, thereby substantially eliminating energy wasting wakes and cavitation.

An energy efficient ship is achieved by powering the ship using at least one propulsion level, each propulsion level having large grids at the forward and stern ends of the ship and side channels incorporating turbines that move water through the ship, rather than around the ship, thereby substantially eliminating energy wasting wakes and cavitation.

Maintenance personnel need to be safely transferred to offshore structures from marine vessels in varying sea and weather conditions. Disclosed herein is a control system for a marine vessel (100) having a propulsion and steering system (101) and a fender arrangement (102) at the bow of the marine vessel to provide contact between the marine vessel and an external structure (103). The control system comprises force, pressure, torque or strain sensors and a controller. The force, pressure, torque or strain sensors measure force, pressure, torque or strain that are indicative of forces between the fender arrangement (102) and the external structure (103). The controller controls the operation of the propulsion and steering system (101) to substantially obtain or maintain desired forces between the fender arrangement (102) and the external structure (103) based on the force, pressure, torque or strain measurements from the force, pressure, torque or strain sensors.

A rechargeable robotic pool cleaning apparatus having a first water pump for providing a downward thrust force, a second water pump for providing at least a rearward thrust component, and a third water pump for providing at least a forward thrust component, the apparatus being buoyant when the pumps are not activated and including adjustable flap valves, baffles and nozzles to alter the outflow direction of at least some of the jet streams of water produced by the pumps so as to produce any one or more of a vertical, forward, rearward, and sideward thrust component depending upon the positioning of the baffles and/or nozzle members. At least one main controller is electronically coupled to a rechargeable power source for controlling the operation of the pumps in various combinations for moving the apparatus both vertically and horizontally in the body of water.

Described herein are paddlecraft such as kayaks modified to include a motor to assist the paddling action of a user of the paddlecraft. The paddlecraft has a motor driven propeller located in an elongated channel within a paddlecraft base which drives water flow from an inlet side to an outlet side of the motor driven propeller via the elongated channel to drive movement of the paddlecraft. At least one movement sensor may be located on the paddlecraft and motor driven propeller actuation is driven by a user when the at least one movement sensor senses paddling movement by the user. A network comprising multiple paddlecraft and movement sensor communication is also described along with a method of assisting a paddlecraft user to generate motion.

A jet propulsor, for use in vehicles or other devices moving in a three-dimensional gaseous or liquid medium such as air or water, has a joint chamber and at least four flow passages which are connected to the chamber with one of their ends, have independently controllable reversible pressure units inside, and are provided with independently controllable nozzles on their other ends. The propulsor pumps gas or liquid from the environment through itself and, because of reaction forces, provides for simultaneously and independently controlled thrust and thrust moment in terms of their value/strength and direction. Spatial control of the thrust vectoring and conditional thrust moment vector can be provided for in the spatial range of a full solid angle.

A jet propulsor, for use in vehicles or other devices moving in a three-dimensional gaseous or liquid medium such as air or water, has a joint chamber and at least four flow passages which are connected to the chamber with one of their ends, have independently controllable reversible pressure units inside, and are provided with independently controllable nozzles on their other ends. The propulsor pumps gas or liquid from the environment through itself and, because of reaction forces, provides for simultaneously and independently controlled thrust and thrust moment in terms of their value/strength and direction. Spatial control of the thrust vectoring and conditional thrust moment vector can be provided for in the spatial range of a full solid angle.

A jet propelled watercraft includes a reverse gate that moves to a first position and to a second position. When the reverse gate is in the first position, the reverse gate causes a vessel body to move forward. When the reverse gate is in the second position, the reverse gate causes the vessel body to decelerate or move backward. A velocity mode selector is used to select a normal mode or a velocity mode. The velocity mode has a maximum velocity different from that of the normal mode. When the reverse gate is in the second position and the velocity mode is selected, a controller is configured or programmed to set an upper limit of an engine rotation speed in the velocity mode to be different from that of the engine rotation speed in the normal mode.

A vessel (2) which floats on water (4) and which generates electricity, which vessel (2) comprises: (i) a hull (6); (ii) at least one water inlet (8) at a front part of the vessel (2); (iii) at least one water outlet (10) at another part of the vessel (2); and (iv) apparatus (12) for generating electricity comprising at least one stator (16) and at least one rotor (18),
and the vessel (2) being such that: (v) water (4) passing from the water inlet (8) to the water outlet (10) causes the rotor to rotate and thereby the apparatus (12) to generate the electricity.

A submersible vehicle is provided which is able to achieve six of freedom utilizing a combination of only two thrusters with no external control planes. Each of the two thrusters can include a plurality of ducts which can be selectively opened or closed, to varying degrees, to achieve six degrees of freedom for both control and propulsion.