I'll be very interested to hear responses to this question. I think my boat is OK, but there has been so much discussion about this topic it makes my head spin. Many years ago, I changed the aluminum bang plate cover, that was beginning to pit, to vinyl and sealed it well; I see no indication of rot or rust on the inside rear transom areas. I find it hard to believe that much water, if any, could be coming in thru the side vents while idle or running. I'm in SoCal, so harsh conditions are rare. The hull tapping process, I'm sure, is valid when done by an expert, but I'll be damned if I can figure it out. Anyway, my engines seem solidly in place and I see no signs of problems, so I'll just continue enjoying my boat.