Just finished a few days on the palmetto trail in south carolina. I started on Hwy 17 near the coast and hiked across the francis marion national swamp and around lake moultrie on the dike. The trail is wide, flat, nicely groomed and marked every mile thru the francis marion. Mud boards were available where they were needed. water was plentiful but finding moving water sometimes took a few miles between flowing creeks. Most of it was deeply brown/yellowish but tastes ok. These are the best maps: http://www.palmettotrail.org/maps.asp.
Other notes:
the halfway creek campsite is nice but the pump does not work. you could get water a bit further down the trail.
the harlstone dam campsite did have a little flowing water on the left about 100 feet south of the campsite.
the witherbee ranger station had one picnic table behind the office building. water was available from the faucet on the back of the vacant residence about 200 yds away. I did charge cell phone on the outlet at the back of the office building.
alligator creek campsite was flat and tree covered. no water immediately near.
the canal rec area campsite was good. the tent site is actually up the trail to the right when you come into the clearing and more away from the road traffic noise. there was a working water faucet near the 2 old wrecked toilets in the rec area picnic grounds. also picnic tables there.
the first few miles of the dike walk is sort of hard surface. it ends near the main road in town. walking down the road 200 yds and a good cafe is on the right. had many choices for fried baloney! after you finish walking through town the dike resumes and is softer. when you get to the railroad bridge, the only way is over the bridge so try to do it when no train is around plenty of room on the left to walk but who wants to cross alongside a rolling train. From there is more dike over to the next much shorter bridge where you head back into the woods.
we stayed at the campsite at the 23 mile point on the map. It was quiet and had a working fresh water pump.
the next day we hit a long road walk and got tired of it quick and hitched up to santee and the motel 8.
I think the trail is mainly for bike riders. we saw some campers but no other hikers. we did see a few groups of bikers. Its probably best for them.