Raw-water cooling

Many marine engines or generators use outside water for cooling directly or through a heat exchanger.

Possible components:

intake through-hull

seacock

strainer

raw-water pump

impeller

heat exchanger

exhaust injection components

A closed seacock, obstructed strainer or failed impeller can rapidly cause overheating.

System layout varies.

Never turn "open the seacock" into a universal blind instruction without identifying the correct valve and system.