The wave slap is a common problem with most of the NTs. After our first night at anchor in our 37, my wife said she wouldn’t spend another night on the boat if I didn’t do something about the guy pounding on the hull with a sledge hammer. The partial fix for the problem was to have the chimes filled in as far forward as possible, without getting into the boot stripe and about 4 foot back from where the water meets the chine. This has pretty much eliminated the slap except when the waves get choppy out. I have pics of my chine job if you’d like to see more.