I have done the Dismal Swamp Canal maybe a dozen times. Here are some tips for going north:
Most boaters start at the Elizabeth City free docks. I have never seen them full. In peak spring season the town used to host a gathering of all cruisers at the docks late in the day. That gathering was started by the "rose buddies", Fred Fearing and Joe Kramer. I had the pleasure of going to one of Fred's gatherings early on in my cruising days. Fred and Joe have both passed but the tradition continues (I hope).
If you want to make the transit in one day, you have to get started early because you need to make the first lock through at South Mills to do it in one day. Check the Elizabeth City bridge opening schedule so you can make it through in the morning in time for the lock.
Another option is to continue through Elizabeth City and anchor at the ox bow a bit up the river. That anchorage is absolutely beautiful if you like peaceful solitude.
You can stop for a bit at the Visitors Center and still make the lock through at the end of the day at Deep Creek, but don't dawdle.
The locks are fairly easy, maybe a 3-5' rise up at South Mills and down at Deep Creek. You hand the canal master a bight of line and he wraps it around a bollard. You then take in line going up or let it out going down to hold you to the face.
After you get through the Deep Creek lock you are blocked by the bridge restrictions from getting to Portsmouth until late if you are a sailboater. I used to hang out at the Chesapeake Yachts long face dock until I can get through the Gilmore Bridge after the peak traffic limitation. Almost all of our trawlers won't have that problem and can continue on to Portsmouth.
There are two nice free docks in tiny side coves on the Portsmouth side, High Street and North Landing. You have to avoid the ferry landings. I have used the High Street one as it is close to a hotel with free wifi in their lobby. That was some years ago and more wifi sites may now be available.
Going south:
For the sailboater I went through the Gilmerton bridge at night and I used to tie up at Chesapeake Yachts. Active Captain cautions that it isn't really free. There is a tiny cove a bit further towards Deep Creek that could hold a boat or two and I once tied up overnight to Deep Creek's bollards.
Like going north, you have to make the first canal opening to get through in a day.
Visitor's Center:
This can be a blast. Some years ago I was single handed cruising and had lots of time. Stopped at Elizabeth City for a couple of days and got to know the cruisers there. One of the lift bridges near Portsmouth was shut down for several days so a half dozen of us headed for the Visitor's Center, rafted up three deep and had a ball for a few days. We did potluck dinners, shared libations and generally partied it up (in a nice way!).
The Visitor's Center has free wifi and will advise you on lock schedules. There is a little State Park interpretive center across the canal. How you get there is interesting. There is folding foot bridge that you use to cross. When a boat comes they fold it back to the shore to make room.
Like I said I have done the Dismal Swamp route a dozen times and the Coinjock route twice. I totally recommend the DS route.
David