Thermal management systems for marine vessels

A thermal management system for a marine vessel, the thermal management system comprising:

• an open loop circuit;
• a pump that pumps water from a body of water in which the marine vessel is operating, through the open loop circuit, and back to the body of water;
• a first closed loop circuit;
• a pump that pumps a first heat transfer fluid through the first closed loop circuit;
• a first component cooled or heated by the first heat transfer fluid;
• a first heat exchanger configured to provide heat exchange between the water and the first heat transfer fluid;
• a second closed loop circuit;
• a pump that pumps a second heat transfer fluid through the second closed loop circuit;
• a second component cooled or heated by the second heat transfer fluid;
• a second heat exchanger fluidly coupled within the second closed loop circuit so as to provide heat exchange for the second heat transfer fluid;
• a valve having first and second valve positions that vary flows of the first heat transfer fluid and the second heat transfer fluid therethrough;
• and
• a control system configured to change between the valve positions of the valve, wherein in the first position the first heat transfer fluid and the water exchange heat with each other via the first heat exchanger without the second heat transfer fluid exchanging heat with the water, the first component exchanging heat via the first heat exchanger without exchanging heat via the second heat exchanger, and the second component exchanging heat via the second heat exchanger without exchanging heat via the first heat exchanger, and in the second position the water exchanges heat with both the first heat transfer fluid and the second heat transfer fluid via the heat exchanger, the first component and the second component each exchanging heat via both the first heat exchanger and the second heat exchanger.