Abstract: A technique for adjusting the trim of a dual electric motor marine propulsion system is provided wherein offset or calibration signal levels are determined through a calibration sequence. The propulsion units are driven in a nominal direction, such as through a “straight-ahead” command. An operator adjusts levels of drive signals to the propulsion units to compensate for deviation from the desired navigational direction, such as due to mechanical and electrical tolerances and variations, as well as due to inherent torques or moments associated with the propulsion units. When the system is determined to navigate the craft in the desired direction, the offset or calibration values are stored. The values are then used during later control of the propulsion units as an inherent trim.

Abstract: A technique is provided for steering and navigating a watercraft. The technique provides for dual electric motor propulsion units aft of a transverse centerline of the watercraft. A forward thruster system is provided forward of the transverse centerline. The rear drive units provide components of thrust for navigating the craft through straight-ahead settings and turning settings. The forward thruster system provides additional thrust components for moving the watercraft in a “sliding” direction, and for providing additional turning thrust. The system is particularly well suited to slow-speed navigation, such as for recreational fishing, as well as for close quarters navigation and docking.

Abstract: A propulsion system for watercraft, such as pleasure craft, fishing boats, and so forth, includes a pair of unitary propulsion units driven by electric motors. The units are positioned to create components of thrust, and a net or resultant thrust to navigate the watercraft in response to operator inputs. The propulsion units may be mounted in a stern region of the craft to provide fore-and-aft navigational thrust, as well as thrust for turning the craft as desired. The rotational speeds of the units are adjusted in cooperation to produce the desired navigational thrust. Props of the units may be positioned within integral recesses within the hull, with motors for driving the props positioned within a drive cavity of the hull. The motors may be reversible to further enhance the controllability and maneuverability of the watercraft.

Abstract: A technique for steering a watercraft includes applying drive signals to first and second electric propulsion systems disposed at locations on either side of a longitudinal centerline of the craft. The drive signals power motors of the systems to drive props at corresponding speeds and directions. The props generated components of thrust which combine to provide a net resultant thrust to steer the watercraft. An operator command device receives operator commands, and a control circuit translates the commands to the drive signals to steer the craft in accordance with the operator commands.