The entry through Rock Hall's breakwater is the only critical part with depths of at least 6' at low tide. Tidal range is about 1.5 feet. Favor red as you pass through the breakwater entrance.
Boats with 7' draft tend to time their passages. The harbor's 2 marked channels have 7'+ all the way to TSE. One channel runs the circumference of the harbor, the other cuts straight across. Straying outside puts you in 3' of water.