Hi and welcome -
can be tricky in portions of FL, GA, SC and NC, not just with air draft
, but draft in general. For example, some places in GA may have 12-14 feet at MHW; at MLW however, depths may hover in the 6-8 foot range. We transited the Mud River/Altamaha Sound area of GA two weeks ago and at near high tide had only
9'-10' in some spots. Careful planning and attention to tide tables is essential.
The maximum fixed bridge clearance is 65' at MHW and I believe this is the standard for the entire ICW. Bridges off of the ICW will vary. There are a great many drawbridges in FL, particularly between Miami
and Ft. Pierce, which are restricted to scheduled opening times. When you arrive in the states, pick up a bridge opening schedule. Most bridges throughout the waterway will open on demand, with limited scheduled opening times to accommodate local road traffic.
Bob's ICW updates page regularly - they've been a huge help with our trip planning on the ICW: www.skipperbob.net/waterway.htm