Re: Boating the Upper Chesapeake
I used the Charlestown ramp a few times with my old 23 footer. There's not much depth in that area, so keep your drive trimmed up until you're in 3' or more. You have a depth finder, right? Easy trailer parking at the Wellwood (don't know how much it costs now).
Anchor Marina has a better ramp IMO, but it's steep and can get busy. Either ramp is close to the Flats. Speaking of the Flats, if you've never been there before I suggest you go near high tide or at least follow another boat. There are no marked channels and the Flats and can be very shallow if you don't know where to go. I think the Flats are easier to access from Perryville or Havre de Grace because they are closer and the natural channel is deeper (but still unmarked).
Water levels in the upper Bay are influenced by more than tides. If the wind is blowing from the south, it'll hold the water in the upper Bay and we can have high water all day. Conversely, wind from the north will push water out of the area and low water will result. Also, excessive outflow from the Conowingo Dam can keep levels high for a week or more, not to mention dumping debris an silt into the Bay.