Ah, planning a cruise is nice therapy for our bitter cold weather.
Dave raises a couple of issues that we need to consider carefully. Since I need practice doing this myself, here area few things I saw in the current predictions this evening. This is probably stuff that you guys already considered:
Slack before ebb at Essington on May 3 is 0912. Slack before flood at Arnold Point (5 nm from Cohansey on my chart) is 1413. So we have 5-6 hours of easy travel (favorable current, slack, or mild head current), just like Dave mentioned, and around 2-3 hours of less easy travel.
My computer chartplotter estimates a little over 8 hours to Cohansey entrance if we average 5 kts (plus another 45 minutes to get to the Hancock Harbor). With favorable current for much of the trip we might do a little better than that, especially using motor assist if the winds aren't right. Since it looks like we'll have a few hours of fighting the current, I'd suggest leaving around 0730 and going against the slowing current at the beginning so we can minimize the accelerating current at the other end. Of course, once the current turns, it will help push us up into Cohansey River.
Ulladh - I know these currents are pretty much the same every year, and you've done this trip several times before. Have you made it to Cohansey in one day before, or is this a first for you?
Assuming we make it to Cohansey, slack before ebb on May 4 at Arnold Point is 0846, and slack before flood is 1510. So we either need to leave really early or pretty late. We may be pretty wiped out after 8-9 hours of sailing the day before, and there's some nice wildlife to see and maybe some opening day activities at the marina, so it's pretty clear that we should leave the marina around 1300 (if we want to go to Ship John) or 1400 (if we skip Ship John) to catch the flood up the river. That would put us at the canal entrance right around 1900, just as the current through the canal is turning in a favorable direction. But this is a lot of sailing on two consecutive days, so I'd be fine stopping at Delaware City for the night if we're growing weary after two long days.
That would put us at Delaware City on Cinco de Mayo, so if they have really good activities planned we could stay there for some of the inspiration that Ulladh found lacking last year.
If not, Lori really loved Chesapeake City in 2010, and the currents through the canal would be timed perfectly for a run over in the morning, spend a few hours in town, and then a run back to Delaware City in the afternoon. We could play it by ear.