Advice on compression #'s
 

I found a great boat going through auction (buddy is a dealer) and their mechanical report stated that all cylinders checked out at 180lbs of compression (6.2L Merc) but that is won't draw water from the out drive. I'm sure the sea water pump is the culprit.

Long story but I know a little bit about the boats' previous life. The boat was very babied, only has 216 hours, and still has the tags on it from getting winterized last year so I'm assuming it isn't a major long term over heating failure. (I fried the pump on a 454 last year just dry cranking it for 2 seconds....)

So is it a safe assumption that if the compression numbers are good and oil is clean that their most likely isn't a catastrophic failure? I figured that if a head gasket went bad over long term the oil should tell the tale....

Re: Advice on compression #'s
 

Sounds like a pretty safe bet to me, Steroman405. If they dry cranked the engine for the compression test that might just kill the sea water pump. Good point to remember for the rest of us too.
If you have any doubts about the head gaskets, have them do a leak down test too