According to the present disclosure there is provided an arrangement for influencing fluid flow, the arrangement comprising: a first section selectively configurable to provide a vortex generator surface, the vortex generator surface comprising a series of laterally aligned projections, to induce vortices in the liquid flow.

An apparatus, including at least one trim tab assembly (100), each including: a mounting base (110) configured to be mounted to a stern of a marine vessel; a trim tab (112) including a nozzle (150); a pivot joint (114) configured to raise and lower the trim tab relative to the mounting base; and an axial flow pump (140) configured to direct a medium flow through the nozzle.

An apparatus, including at least one trim tab assembly (100), each including: a mounting base (110) configured to be mounted to a stern of a marine vessel; a trim tab (112) including a nozzle (150); a pivot joint (114) configured to raise and lower the trim tab relative to the mounting base; and an axial flow pump (140) configured to direct a medium flow through the nozzle.

According to the present disclosure there is provided a liquid flow influencing duct arrangement comprising: a first duct section arranged to receive a liquid flow therethrough, the first duct section defining a first direction through the first duct section from a liquid inlet end to a liquid outlet end; a second duct section defining a second direction through the second duct section from a liquid inlet end to a liquid outlet end, the second duct section comprising a vortex generator surface, wherein the vortex generator surface is arranged to induce vortices in the liquid flow through the first duct section, wherein the duct arrangement further comprises a rotor housed in one of the duct sections.

An electrically-propelled marine vehicle and method of making same, including providing a hull of the marine vehicle and mounting a submersible electric thruster to the hull. The thruster includes a stator assembly and a rotor assembly. The rotor assembly forms an internal cavity with a plurality of magnets arranged radially outwardly of the internal cavity. The stator assembly includes electrical windings that are disposed within the internal cavity of the rotor assembly. The thruster is configured to allow the internal cavity to be flooded with water when the thruster is submerged, and the electrical windings are covered by a protective barrier that prevents the flooded water from contacting the windings. The thruster of the marine vehicle is thus water cooled, and the electromotive forces provided by the windings generate sufficient thrust to propel the marine vehicle through the water.

An electrically-propelled marine vehicle and method of making same, including providing a hull of the marine vehicle and mounting a submersible electric thruster to the hull. The thruster includes a stator assembly and a rotor assembly. The rotor assembly forms an internal cavity with a plurality of magnets arranged radially outwardly of the internal cavity. The stator assembly includes electrical windings that are disposed within the internal cavity of the rotor assembly. The thruster is configured to allow the internal cavity to be flooded with water when the thruster is submerged, and the electrical windings are covered by a protective barrier that prevents the flooded water from contacting the windings. The thruster of the marine vehicle is thus water cooled, and the electromotive forces provided by the windings generate sufficient thrust to propel the marine vehicle through the water.

A traction device for towing an object along a water surface or through a body of water, the traction unit comprising at least one propulsive engine. The device device has a common center of gravity, center of thrust and center of buoyancy (13). A bridle (17) is attached to turn about an axis (14) through said common center (13). The bridle (17) has an attachment (18) at a distal end from the turn axis (14) to attach a tow line extending to the towed object.

A traction device for towing an object along a water surface or through a body of water, the traction unit comprising at least one propulsive engine. The device device has a common center of gravity, center of thrust and center of buoyancy (13). A bridle (17) is attached to turn about an axis (14) through said common center (13). The bridle (17) has an attachment (18) at a distal end from the turn axis (14) to attach a tow line extending to the towed object.

An electrically-powered unmanned marine vehicle and method of making same, including providing a hull of the marine vehicle and mounting a submersible electric thruster to the hull via a mounting interface of the thruster. The thruster includes a stator assembly and a rotor assembly. The rotor assembly forms an internal cavity with a plurality of magnets arranged radially outwardly of the internal cavity. The stator assembly includes electrical windings that are disposed within the internal cavity of the rotor assembly. The thruster is configured to allow the internal cavity to be flooded with water when the thruster is submerged, and the electrical windings are encapsulated with a protective barrier that prevents the flooded water from contacting the windings. The thruster of the marine vehicle is thus water cooled, and the electromotive forces provided by the windings generate sufficient thrust to propel the marine vehicle through the water.

An electrically-powered unmanned marine vehicle and method of making same, including providing a hull of the marine vehicle and mounting a submersible electric thruster to the hull via a mounting interface of the thruster. The thruster includes a stator assembly and a rotor assembly. The rotor assembly forms an internal cavity with a plurality of magnets arranged radially outwardly of the internal cavity. The stator assembly includes electrical windings that are disposed within the internal cavity of the rotor assembly. The thruster is configured to allow the internal cavity to be flooded with water when the thruster is submerged, and the electrical windings are encapsulated with a protective barrier that prevents the flooded water from contacting the windings. The thruster of the marine vehicle is thus water cooled, and the electromotive forces provided by the windings generate sufficient thrust to propel the marine vehicle through the water.