Annapolis to Cape May, NJ
Last year I was told by the local NOAA office to use this info for the C & D Canal passage:
If from NJ, wait outside of the canal near the Salem Nuclear Plant until low tide, then wait for an addl 3 hours for the tide to go half way up.
Just north of the Nuc plant, on the NJ side is a safe spot to anchor while you wait for the correct tide. At that time begin your travel thru the canal. By the time you get half way to the Chess side of the canal their tide will be on the way down and the current from the canal will be flowing to the Chess. You will have the current with you all of the way thru from the Del bay to the Chess Bay.
I have done it and it works.
I used the same logic on the return trip and is was just as clean.
Good luck and have a safe trip.