A saildrive arrangement (1) which comprises an upper unit (13) to be positioned inside a hull (5) of a sailboat (7) and a lower unit (14) which is arranged to protrude from the bottom (6) of the hull (5). The upper unit (13) comprises an input shaft (4) to be connected to an engine (2) and the lower unit (14) comprises a propeller shaft (9). A brake (15), for locking the rotational movement of the propeller shaft (9), is located in the upper unit (13). The saildrive arrangement (1) is incorporated into a sailboat (7) with a hull (5) and an engine (2).

An outboard motor comprising a first propeller shaft and a second propeller shaft, wherein the second propeller shaft is arranged concentric with the first propeller shaft, and wherein the first propeller shaft is connected to a first power transfer arrangement to rotate the first propeller shaft in a first direction, and wherein the second propeller shaft is connected to a second power transfer arrangement to rotate the second propeller shaft in a second direction opposite to the first direction. The outboard motor comprises a first electric motor having a first motor shaft, and a second electric motor having a second motor shaft, wherein the first motor shaft is connected to the first power transfer arrangement, and wherein the second motor shaft is connected to the second power transfer arrangement. Disclosed is also a method for driving propeller shafts of an outboard motor.

An objective of the disclosure is to provide a simulation method for a two-stage plunger pressurized common rail fuel system of a marine low-speed engine. The method includes: first setting initial status parameters, such as a control step of a system model, a total time of a calculation process, and structure parameters and pressures of components; and then establishing a mathematical model of a fuel booster unit, a mathematical model of a high-pressure fuel pipe and a mathematical model of a fuel injector based on a MATLAB simulation platform, and connecting input and output parameters of the models to realize data transfer between the models. By considering one-dimensional (1D) spatial fluctuations in the high-pressure fuel pipe, the disclosure establishes a high-precision model of the fuel system, which provides an effective method for designing and calculating detailed pressures in the common rail fuel system.

Systems, assemblies, and methods for operating a marine motor are provided herein. An example motor system includes a motor, a battery, and a processor. The processor is configured to receive a user input indicating a desired speed, determine a charge level of the battery, determine an optimized speed or propulsion of the marine motor based on the desired speed and the determined charge level of the battery, and transmit a signal to the motor to operate accordingly. The processor may generate a correction factor based on at least one of the determined charge level of the battery, a boat speed profile curve, and a boat travel distance curve; and determine the optimized speed or propulsion by applying the correction factor to the desired speed. Thus, an eco-mode can be provided to help maintain a high level of battery charge while still enabling desired use.

In a power supply system for a watercraft, a controller in a first state connects a first electric circuit to a third electric circuit to supply electric power from a first engine battery to an electric device, and disconnects a second electric circuit from the third electric circuit to charge a second engine battery by a second generator. In a second state, the controller connects the second electric circuit to the third electric circuit to supply the electric power from the second engine battery to the electric device, and disconnects the first electric circuit from the third electric circuit to charge the first engine battery by a first generator.

In a power supply system for a watercraft, a controller in a first state connects a first electric circuit to a third electric circuit to supply electric power from a first engine battery to an electric device, and disconnects a second electric circuit from the third electric circuit to charge a second engine battery by a second generator. In a second state, the controller connects the second electric circuit to the third electric circuit to supply the electric power from the second engine battery to the electric device, and disconnects the first electric circuit from the third electric circuit to charge the first engine battery by a first generator.

A power supply system for a watercraft includes a first battery, a second battery, and a battery management device. The battery management device connects the first battery to a first engine to supply an electric power from the first battery to start the first engine. The battery management device connects the second battery to a second engine and a third engine to supply an electric power from the second battery to start the second engine and the third engine.

A fuel supply apparatus mounted in a fuel tank has a fuel pump portion for sucking a fuel stored in the fuel tank and then discharging the fuel to the outside. The fuel supply apparatus includes a harness that is connected with an external power source; a power-sending connector portion a power-sending connector portion that is provided in a harness and has power-sending terminals having respective spring portions, a power-receiving connector portion that is provided in a fuel pump portion and has power-receiving terminals to be connected with the power-sending terminals, respectively, when contact pressure based on elastic force of the spring portions, as elastic portions, is provided thereto, and an insulator that covers at least base portions of the power-receiving terminals and at least parts of the spring portions of the power-sending terminals when the power-receiving terminals are connected with the power-sending terminals.

A fuel supply apparatus mounted in a fuel tank has a fuel pump portion for sucking a fuel stored in the fuel tank and then discharging the fuel to the outside. The fuel supply apparatus includes a harness that is connected with an external power source; a power-sending connector portion a power-sending connector portion that is provided in a harness and has power-sending terminals having respective spring portions, a power-receiving connector portion that is provided in a fuel pump portion and has power-receiving terminals to be connected with the power-sending terminals, respectively, when contact pressure based on elastic force of the spring portions, as elastic portions, is provided thereto, and an insulator that covers at least base portions of the power-receiving terminals and at least parts of the spring portions of the power-sending terminals when the power-receiving terminals are connected with the power-sending terminals.

An electric outboard motor assembly is disclosed. In one example, the electric outboard motor assembly includes a battery pack located in an upper unit and a propeller assembly located in a lower unit. A motor assembly is located in a middle unit between the upper unit and the lower unit. The electric outboard motor assembly may also include a thermal management system.