NOT! What Bozo made that remark? A barroom expert isn't worth the booze he drinks.

The main issue with raw water cooling is the uneven cooling as the raw water proceeds through the block - too cold when it starts it's path and too hot at the end.

I sailed in sweet water for 20 years before ocean sailing. The only concerns I would have on buying a salt water boat are the condition on the standing and running rigging.

Question: Did the engine pictured get water in it's cylinder? Bad exhaust design? Vented loop failure?