A marine propulsion system, supported by a strut, which comprises an inner propeller shaft supporting a first propeller adjacent a trailing end thereof, and the inner propeller shaft is connected to the drive shaft for receiving and supplying a first portion of torque to the first propeller as well as transfer thrust, generated by the first propeller, along the inner propeller shaft back to the drive shaft. An outer propeller shaft supports a second propeller adjacent a trailing end thereof, and the outer propeller shaft surrounds the inner propeller shaft. A planetary gear assembly receives a second portion of the torque and supplies the torque to the outer propeller shaft so that the second propeller rotates in an opposite direction to the first propeller. A portion of the planetary gear assembly is accommodated vertically above a flat end face of the strut for reducing hydrodynamic drag of the strut.

A hybrid marine drive unit mounted to a transom. The drive unit includes a drive housing rigidly mounted on the transom, a propelling unit rotatable about a vertical axis and mounted to a lower surface of the drive housing, and a transmission with at least a vertical drive shaft located in the drive housing and extending into the propelling unit, which vertical drive shaft is arranged transmit drive torque from at least one of multiple sources of drive torque. The vertical drive shaft is operably connected to at least one first source of drive torque arranged within the drive housing, and the vertical drive shaft is operably connected to a horizontal output shaft extending into the drive housing through the transom.

A hybrid marine drive unit mounted to a transom. The drive unit includes a drive housing rigidly mounted on the transom, a propelling unit rotatable about a vertical axis and mounted to a lower surface of the drive housing, and a transmission with at least a vertical drive shaft located in the drive housing and extending into the propelling unit, which vertical drive shaft is arranged transmit drive torque from at least one of multiple sources of drive torque. The vertical drive shaft is operably connected to at least one first source of drive torque arranged within the drive housing, and the vertical drive shaft is operably connected to a horizontal output shaft extending into the drive housing through the transom.

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.

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.

A method for shifting multi-speed transmissions of marine propulsion devices each having a power head and a shift schedule for shifting between first and second gears to transmit torque from the powerhead. The method includes configuring the transmissions of leader and follower marine propulsion devices to shift when shift schedules of the leader and of the follower indicate shift recommendations, respectively. The method further includes receiving a request to shift the transmission of the leader when the shift schedule of the leader indicates the shift recommendation. The method further includes determining whether conditions are met for the follower to follow the leader in shifting. The method further includes automatically requesting, when conditions are determined to be met for the follower to follow the leader, to shift the transmission of the follower so as to be coordinated with shifting the transmission of the leader.

A method for shifting multi-speed transmissions of marine propulsion devices each having a power head and a shift schedule for shifting between first and second gears to transmit torque from the powerhead. The method includes configuring the transmissions of leader and follower marine propulsion devices to shift when shift schedules of the leader and of the follower indicate shift recommendations, respectively. The method further includes receiving a request to shift the transmission of the leader when the shift schedule of the leader indicates the shift recommendation. The method further includes determining whether conditions are met for the follower to follow the leader in shifting. The method further includes automatically requesting, when conditions are determined to be met for the follower to follow the leader, to shift the transmission of the follower so as to be coordinated with shifting the transmission of the leader.

A method for shifting a multi-speed transmission for transmitting rotation between an input shaft and an output shaft for a marine vessel. The method includes providing a multi-speed transmission having first and second gears engaged by actuating first and second clutches, and providing first and second pressure sensors that measure first and second pressures within the first and second clutches, respectively. The method further includes performing a first shift from the first gear to the second gear by de-actuating the first clutch a first delay after the second clutch is actuated, then measuring the first and second pressures and determining a first shift pressure at which the first and second pressures are substantially equal while performing the first shift. The method further includes comparing the first shift pressure to a first pressure threshold range and adjusting the first delay when the first shift pressure is outside the first pressure threshold range.

A method for shifting a multi-speed transmission for transmitting rotation between an input shaft and an output shaft for a marine vessel. The method includes providing a multi-speed transmission having first and second gears engaged by actuating first and second clutches, and providing first and second pressure sensors that measure first and second pressures within the first and second clutches, respectively. The method further includes performing a first shift from the first gear to the second gear by de-actuating the first clutch a first delay after the second clutch is actuated, then measuring the first and second pressures and determining a first shift pressure at which the first and second pressures are substantially equal while performing the first shift. The method further includes comparing the first shift pressure to a first pressure threshold range and adjusting the first delay when the first shift pressure is outside the first pressure threshold range.

A method for shifting a marine propulsion device transmission between first and second gears transmitting torque from a powerhead with a redline RPM. The transmission has a transition time for completing a shift. The method includes measuring an RPM of the powerhead, comparing the RPM to a first threshold, and starting a timer when the RPM exceeds the first threshold. The method includes measuring the RPM of the powerhead after the first threshold is exceeded, comparing the RPM to a second threshold, stopping the timer when the RPM exceeds the second threshold, determining an elapsed time between starting and stopping the timer, and determining a shift RPM based on the determined elapsed time, the redline RPM, and the transition time of the transmission. The method includes controlling the transmission to shift when the RPM measured for the powerhead reaches the shift RPM such that shifting completes before the redline RPM.