Gordon et al, Am looking for recommendations concerning rebuild/replacement of Yanmar 3HM35F in my Hunter 37.5. A year after buying the boat, the engine has died apparently from water contamination. The original complaint began in July with hard starting and stalling when changing gears. The marina replaced the filters, then the fuel pump, then the injectors were serviced, then the injector pump rebuilt, and finally after all of that, a compression check revealed only one third of required compression. In between the fuel pump and the injectors, the engine started using about a third of a quart of oil per hour of operation. Until then, it would use perhaps a half quart in 15 to 20 hours of operation. Throughout, the oil was always black on the filler cap and dip stick never showing signs of browning or graying. I now must decide whether to rebuild or replace the engine? The marina tells me they can pull it and send it to Mack Boring for rebuild more inexpensively than replacing the engine???? Can't say I am real thrilled with this whole situation. Can I assume a short block could be ordered and arrive on-site before the engine is pulled out of the boat??? If so, what parts are generally included on a short block? I have a high output alternator, etc. that I really don't want to replace with a complete engine. My sketism is telling me that rebuilding the engine is at best an unknown. Needless to say, I am already more than a few dollars into this thing with real poor results. Even toying with doing the job personally. I don't want to, but! Thanks.