I would not trust using someone else's boat measurement or even the manufacturer. I would measure it myself. Just search “boat idiots” on utube to see how many boats hit the bridge they are trying to pass under.
I have a 92 MT 34DC. My clearance is 18 1/2
I've made it under 14' with EVERYTHING down. 22' is what I plan on for going fully erect.
I had no problems on the Champlain Canal. The bridge to the Ft Edward branch was tight but we made it.
I'm being shrinkwrapped as I type so I cant measure anything.
Bob328 is your mast mounted on your aft cabin roof or flybridge deck? Thanks.