Thanks to everyone for the really informative posts. I had a retired surveyor friend read through these to help me sort them out. Here's his take on it all.
On oil canning, many owners mistake some deck flexibility for oil canning, when in reality they're describing a deck problem from delamination, sometimes calling it a trampoline in bad cases. Also, in a seaway, many lightly built boats will flex noticeably, and this, too, could be called oil canning by an untrained person. That kind of flexing almost always causes hairline crazing or cracks in the surfaces of gelcoat, particularly in the "sharp" corners or where the molded shape changes greatly. The term "oil canning" originated when motor oil was sold in quart cans where the top could be easily popped in and would pop out when you took your finger off. Sort of a pucker. And similar to what you'd see on a can of food that has gone bad, where the top has a slight dome that you can pucker.
Feel free to listen to some surveyor who wasn't there or from the consensus of a group of knowledgeable sailors who were and know the what "deck flexing" is - this has absolutely nothing to do with the issue here and most surveyors should be able to tell the difference...
Regarding the flat hull and pounding, I said both were relative terms - this boat has/does both compared to similar sized and priced competitors - again, your choice.
Last edited by k1vsk; 02-18-2009 at 10:34 AM.