You definitely need a good chart, a tidal chart, and a table of the tidal changes, as the currents can have a tremendous effect on your progress.
Compared to the Chesapeake Bay, there seem to be both a greater number of navigational hazards outside the main channel and a greater number of ships transiting the channel in the Delaware Bay, so it is a more difficult passage, which requires a constant lookout.
In addition, the Delaware Bay is not protected from ocean swells running from the Southeast as the Chesapeake Bay is. In the warmer months, the typical shore breeze builds so by the afternoon so you may find yourself beating into wind and waves/chop toward the mouth of the Delaware Bay. If the tide is also running against you, it will be difficult to make good speed over the ground.
It is challenging to make it from the C&D canal to Cape May in a relatively small sailboat during daylight hours.