I went to look at a boat last weekend (a Bristol 29.9) and loved it until we talked about the engine.
The ad said "diesel with 800 hours" and I thought that might mean a newer engine (how would I know how many hours a boat might be motored in a year?). Well it is 800 hours on the original 1978 engine and the boat has raw water cooling.
Looking online*, I see that maybe the 800 hours is not an issue because a well maintained one can get 5,000 (if you believe the internet) but the 35 years of salt water going in and (hopefully) out still scares me.
After the visit, I told my wife "Lovely boat, but we'd need to replace the engine."
Was that correct? Would a reasonable sailor replace an engine in this situation or could I just make sure it runs and trust it for a few years?
My mooring is on a river with a swift current and 2 draw bridges, so running the engine to failure is not an option.
Finally, if saltwater corrosion is going to be the cause of death, what are the initial symptoms? Is there a way to determine the level of corrosion?
* The Life Expectancy of the Marine Engine - BoatSafe.com