I just did some homework. My old NOAA Chart of the Mystic River shows the horizontal clearance for Draw Bridge is 65 feet...keeping in mind the bridge is a Bascule bridge...ie: It
"Tips Up" to open...it's overhang when fully UP..might impinge on the masts and yards of the ship.
The
Beam of the Morgan is 27 feet 6 inches. The beam of a vessel does NOT include "Fixed" whale boat davits, rigging, and other stuff which extends beyond the (Official) beam of the hull.
My experience with navigating shallow channels with a sailboat (C&C 32) which had a draft of 5' 8", was this:
Approach the shoal area on a
Rising Tide. IF you ground...the TIDE is in your
favor..and will lift you off.
NB