A system for controlling a marine vessel includes a processor, a propulsion system, and a directional system. The processor is disposed onboard the marine vessel and obtains a trip plan that includes designated operational settings of the marine vessel for a trip along a waterway. The propulsion system is communicatively coupled with the processor and generates propulsion to move the marine vessel according to the designated operational settings of the trip plan. The directional system is communicatively coupled with the processor and steers the marine vessel according to the designated operational settings of the trip plan. Operating the propulsion system and the directional system according to the designated operational settings of the trip plan reduces at least one of fuel consumed or emissions generated by the marine vessel relative to the marine vessel being propelled or steered according to one or more plans other than the trip plan.