Abstract: A thermal management system for a marine vessel. The thermal management system includes an open loop circuit and a pump that pumps water from a body of water, through the open loop circuit, and back to the body of water. The thermal management system further includes a closed loop circuit and a pump that pumps a heat transfer fluid through the closed loop circuit. A heat exchanger is configured to exchange heat between the water and the heat transfer fluid. The thermal management system includes multiple components each cooled or heated by the heat transfer fluid. A valve has valve positions configured to vary a sequence that the heat transfer fluid is conveyed to the components so as to vary how the components share the heating and cooling from the heat transfer fluid and from the water from the body of water via the heat transfer fluid.