You'll be fine in a 17-18 ft boat. I have a 17ft with a 6 degree bottom. I contemplated getting a bigger boat but on top of more $$$, the side height and other measurements on my boat were virtually the same on boats in the 19-20ft range I was looking at so it didn't make sense. Just make sure you're checking the marine forecasts. When it's too crappy for the salt and you still want to go out, hit freshwater instead.