PT:
Crewed on a northbound boat from NC to Norfolk.
The gang has already mentioned the key points..........many but not all bridges have Clearance height (calculated by using the water level) marks on pilings, etc near the bridge ..........some are brightly painted others suffer from wear & tear.
It can be nerve racking if it's close (like us)..........the water is moving, there are often
lights & bridge supports hanging down below the max height........so we had to dodge then as we aimed for the highest section of each span.....................after that it was just timing & communicating (if necessary) with manned bridges
I used a cruising handbook = The Intracoastal Waterway - Norfolk to Miami by Jan & Bill Moeller. It worked real well & was very accurate. It tracks the whole route by milemarkers. Also includes info on marinas,
fuel, sights, etc.
