Systems and methods for controlling speed of a marine vessel

A method for controlling a speed of a marine vessel having a first propulsion device that produces a first thrust to propel the marine vessel and a second propulsion device that produces a second thrust to propel the marine vessel, the method comprising:

• receiving a trolling mode command from a first user input device with a control circuit;
• and
• thereafter varying a trolling speed of the marine vessel with the control circuit by selecting between doing one or more of the following in response to an input from a second user input device:
• varying a speed of a first engine of the first propulsion device and a second engine of the second propulsion device;
• and
• varying one or more alternative operating conditions of the first and second propulsion devices;
• wherein varying the one or more alternative operating conditions comprises one or more of the following:
• varying a slip of first and second transmissions of the first and second propulsion devices, respectively;
• and
• varying orientation of the first and second propulsion devices about first and second steering axes, respectively, so as to vary a splay angle between a direction of the first thrust and a direction of the second thrust.

A method for controlling a speed of a marine vessel having first and second propulsion devices with first and second engines operatively connected to first and second transmissions, the first and second propulsion devices controlled by a control circuit communicatively connected to a throttle/shift lever and a joystick, the method comprising:

• determining if the throttle/shift lever has been placed in a forward detent position, and if so:
• determining if the joystick has been actuated in a forward direction, and, if so doing one of the to following:
• decreasing a splay angle between a direction of thrust of the first propulsion device and a direction of thrust of the second propulsion device;
• decreasing a slip of the first and second transmissions;
• and
• increasing a speed of the first and second engines;
• and
• determining if the joystick has been actuated in a rearward direction, and, if so doing one of the following:
• decreasing the speed of the first and second engines;
• increasing the slip of the first and second transmissions;
• and
• increasing the splay angle;
• wherein the control circuit prioritizes one of decreasing the splay angle and decreasing the slip over increasing the speed of the first and second engines in response to repeated actuation of the joystick in the forward direction;
• and
• wherein the control circuit prioritizes decreasing the speed of the first and second engines over one of increasing the slip and increasing the splay angle in response to repeated actuation of the joystick in the rearward direction.