The Savannah river is also a great dive. In the summer (barring periods of significant rain) vis can be 15'+. N. Augusta Boat landing is a good dive. A good plan is swim (dive) over to the GA side from the boat ramp. Look for interesting stuff from the old dump (stuff from many years ago was just pushed into the river). Swim upriver until about 1/3 air remaining, swim back across to SC side and enjoy the drift back to the ramp (don't miss the ramp, next exit is a bit far. This part of the river is in the fall line, so there are large rocks, boulders making up the bottom. Depth about 18' max.
The 5th street drift is also a great dive. It starts with a shipwreck in 15' of water - bow, boilers, planking. It is an hour +- drift dive to the old marina. The supports for the Hwy 1 bridge are interesting, the remains of the old Hamburg cotton docks (1/3 of the way out from the SC side) are interesting and have fish. On the GA side, you'll find large bolders at the shore and the remains of the old hamburg bridge.
As you've said, there is Clark Hill Lake. Lots of stuff to see there. Of course there is the airplane, but there is so much more. PM for details. Come join us. As for dive clubs - I'm not aware of an active club in the area. Regarding the tank - the IWANTA mag (found in convenience stores) often has some listed. Careful though, it is easy to overpay or get a tank close to out of hydro. I suggest that you think steel 100cf or 120cf. Great for those long drift and deep lake dives. See Ron at Neptune Dive and Ski.
