These samples are from a Grand Banks trawler at 8 gallons sucked through the raw water system. To the naked eye you would be hard pressed to tell the difference between these two samples as they shot out the exhaust.


The sample on the left was taken at the end of gallon 8 and the sample on the right is straight out of the bottle. Raw water pumps, strainers, oil coolers, gear coolers, heat exchangers, water lift mufflers and refrigeration coolers are expensive. Propylene glycol is cheap...