I run a 27' Wellcraft Nova 3 with twin Mercruiser 350/Alpha 1 I/O's with raw water cooling out of Newport Beach CA.. Boat stays on trailer and only goes in the water on days used. Unfortunately, I only spend about 1/3 of my time in CA and the blance on the east coast. Boat sits unused for up to 6 or 8 weeks at a time, but I get to use it all year long(no layup). Last trip out, I wound up with severly low oil pressure in starboard engine. Opened sunpad and found severe oil leakage which appears to be at front main seal or front of oil pan. Difficult to see since engines are in tight quarters. Adding oil restores pressure, but it leaks right out in a short period of time.<br /><br />Did a compression test and all is good. Also cut open oil filter and found no metal filings. Since all else looks good, I'm pulling engine in late July. Will replace oil pan gasket, oil pump and screen, front and rear main oil seals, timing chain and sprokets, timing cover and gasket, water pump and a few other misc. items. Some replacements are simply because the parts will be accessible. Engine already has a brand new exhaust system. Anyone experienced something similar? Any advice? A mechanic did mention to me that he has seen the oil pan in these engines actually rot out. If thats the case I'll get a pan locally. 