320 beam
The waterline beam is really not at issue as far as getting into a slip is concerned, the "beam" of the 320 is 11ft 9in. I have slid mine into a 12ft slip, but do not like it. There can't be any part of the slip amidship on both sides or no fender. If you face the possibility often, the thin fender boards are very helpfull. Most slips are usually 14ft and that is great! Good luck!