The poor exhaust design that leads to water intrusion became mort prevalent around 2000 and hull numbers 198 or so when Mainship started using the Cat 3126 engines. They did not take advantage of the full engine room height with a dry riser thus allowing water to back into the turbo and engine during rough weather when the engine was either not running or at idle.
There were two boats that were trailered (by Mainship) to Ca and were loaded bow down. Both were ruined. Mainship refused to admit there was a design issue with the exhaust and blamed it on a "mistake" of shipping bow down.
Even after several more engines became hydrolocked due to water intrusion Mainship kept denying the issue and continued to use the poor design.
Eventually Mainship performed a fix under a "silent recall" program (they would only repair if someone complained to them). The fix was also poor but it was cheap to do.
Bottom line if you buy one of these models, change the exhaust riser to take full advantage of the engine room height.
Ex boats: 1983 40 Albin trunk cabin, 1978 Mainship 34 Model 1
New Port Richey, Fl