Coolant / Antifreeze

Coolant, often referred to as antifreeze, is a specialized heat-transfer fluid essential for the operation of closed-loop marine cooling systems. Unlike raw-water cooling systems that draw water directly from the environment, closed-loop systems circulate a mixture of water and ethylene glycol or propylene glycol through the engine block to regulate internal temperatures. The primary function of this fluid is to absorb heat from the engine cylinders and transfer it to a heat exchanger, where the heat is then dissipated into the surrounding seawater.