The lubrication of a steerable thruster of a marine vessel is based on splash-type lubrication at the pod and full bath lubrication in the stembox and in the shank. The lubrication oil enters the pod both from the stembox and the shank via a constriction and directly from the oil tank. The oil is further circulated from the pod to the oil tank by means of pumps.

A propulsion assembly of a ship or floating platform includes a housing within a hull or platform. The housing is watertight except for an opening external to the hull. A stationary motor is arranged in the hull external to the housing. A thruster is external to the hull to generate thrust on the ship or floating platform. A telescopic driving shaft passes sealingly through a housing wall to connect the motor and the thruster and to transmit movement from the motor to the thruster. The thruster retracts within the housing through the opening. A separate submersible movable hatch is disconnectable from the thruster and the housing and passes externally to the hull, and seals the opening to form a watertight closed chamber. A fluid evacuation device evacuates fluid within the closed chamber so the thruster, when retracted in the housing and closed by the hatch, forms the closed chamber.

Apparatus to control transmission of data, the apparatus comprising: a controller configured to: receive data from at least a first sensor within an azimuth thruster; control storage of the received data in memory; determine whether at least one criterion is satisfied, the at least one criterion varying with the relative positioning of a first antenna mounted on a lower housing of the azimuth thruster and a second antenna mounted on an upper housing of the azimuth thruster, the lower housing being configured to rotate relative to the upper housing; and control transmission of the stored data from the first antenna in response to determining that the at least one criterion is satisfied.

An auxiliary hull unit detachably mounted to a transom on a marine vessel, wherein the hull unit is mounted at least partially below the water line of the vessel and arranged to extend rearwards parallel to the rearward extension of hull sections adjacent to the hull unit. The hull unit comprises a rear hydrofoil system for the marine vessel; the rear hydrofoil system comprising at least one pair of foldable hydrofoils which are pivotable in a lateral direction relative to the hull unit, wherein each hydrofoil is controllable by at least one actuator for displacement of the at least one pair of foldable hydrofoils in the lateral direction of the hull unit between a stowed position and a deployed position. The hull unit can be provided with a propulsion unit.

A stern drive is for propelling a marine vessel in water. The stern drive has an upper drive unit with a lower mounting surface; a lower gearcase coupled to the lower mounting surface and a trailing end surface that is angled relative to the lower mounting surface; and a propeller shaft extending forwardly from the lower gearcase and being configured to rotate a propeller for pulling the marine vessel in the water. The upper drive unit and the lower gearcase are configured such that when a forward side of the lower gearcase impacts an underwater obstruction, the lower gearcase is caused to pivot relative to the upper drive unit until the trailing end surface impacts the lower mounting surface, which thereby causes the lower gearcase to completely uncouple from the upper drive unit.

An auxiliary hull unit is detachably mounted to a transom on a marine vessel. The hull unit is mounted at least partially below the water line of the vessel and arranged to extend rearwards parallel to the rearward extension of hull sections adjacent to the hull unit. The hull unit has a rear hydrofoil system for the marine vessel. The rear hydrofoil system has at least one pair of foldable hydrofoils which are pivotable in a lateral direction relative to the hull unit. Each hydrofoil is controllable by at least one actuator for displacement of the at least one pair of foldable hydrofoils in the lateral direction of the hull unit between a stowed position and a deployed position. The hull unit can be provided with a propulsion unit.

A marine propulsion device includes a motor including an output shaft, a drive shaft extending in a vertical direction of the marine propulsion device, and a cooling device. The motor is disposed so that an extension direction of the output shaft is a direction perpendicular to the vertical direction. The cooling device includes an intake port taking water outside the marine propulsion device into the marine propulsion device, a motor water jacket provided in the motor and cooling the motor, a water pump disposed below the motor and sending water taken into the marine propulsion device from the intake port to the motor water jacket as cooling water, and a first cooling water passage connecting a discharge port of the water pump to an inlet port of the motor water jacket.