You should buy the Mid Atlantic Waterway guide and the Northern Waterway guide. Expensive, but there good for years and they have good data on marinas, anchorages, etc. The top of the Chesapeake there are good anchorages in the Sassafras and Bohemia rivers. 6 miles down the Delaware to starboard is the Reedy Is. dike, pass thru the marked opening for another anchorage. The Cohansey R. looks to far off course, it isn't.
Anchor at the entrance or tuck further up river its a great spot. Plan carefully that river can become a nightmare in a very few minutes... or its like sailing on a pond. Try to keep the current with you and ease off the channel when a ship appears, you'll do fine! Also forget restricted, means nothing! Have fun.