Xluke - currents are reported as ebb (-) and flood (+). Ebb is outbound on a river, flood is inbound. Keep in mind that on a large river like the Delaware, you need to look at the "progress" of the flood or ebb. In other words, the river will start to flood at its mouth and then work its way up, so it won't reach max current at the head of the river until some time after it reaches max flood at the base of the river. Ditto on the ebb - it will start ebbing (flowing outbound) at the mouth of the river sooner than the head. This can work to your advantage or disadvantage. If you time it right, you can "ride the ebb" on the way down the Delaware and gain an extra knot or two of boat speed. As Vasco said, there's not an enormous amount of difference, but when you have to motor for an entire day I wouldn't mind saving even an hour! I hate to tell you this, but in my opinion the trip from the Chesapeake side of the C&D Canal all the way to Cape May is not a fun one, but can be a highly technical motoring and navigational experience (we did it in pea soup fog).
By the way - on the C&D Canal, the flood tide/current runs to the east and the ebb to the west.
It looks like you're best to leave the Delaware side of the C&D canal mouth around 4:42AM. Boy does that bring back memories
We left Delaware City (just north of the C&D) at 4:30AM in pea soup fog and didn't arrive in Cape May until 6PM.