Air draft of a CD 31?

[Capt Hook]

Does anyone know the air draft of a CD-31?
I’m guessing it’s somewhere around 45’ not counting any instruments or antennae.
I’d rather not guess when the bridge I usually have to go under has a clearance of 45’.
The bridge tender always asks my mast height and I always say 47’ to be safe and they’ve always opened for me although one tender told me it looked like I could clear when I was approaching.

[Jim Walsh]

I would avoid a technical discussion with a bridge tender as he bears no responsibility should damage occur. A passing wake from a thoughtless boater could increase your air draft by a yard or more depending on where the bridge is located and the fetch of the body of water it sits on. My mast is 46’ from the base to the truck. My VHF antennae is three feet higher. My mast base sits approximately 18” below the waterline.
I’ve never had a reason to be any more precise, nor would I allow a bridge tender to second guess the safety of my vessel. I have seen two sailboats lose their rigs beneath bridges, both due to engine failure, and the current was not in their favor. This was a bascule bridge on the Niantic River. All of us with sailboats stayed well clear till the tender blew the whistle to inform us he was all the way up and the gear had been locked down.

[Capt Hook]

Thanks, Jim.