I’ve been to Jocassee a couple of times, and was basically unimpressed. Viz is typically 5 to 15 feet. Mid-week it might get up to 20 feet. Jocassee is cold. Even when I was there in late July, the water was in the low 70’s at 25 feet, and drops much lower at that first thermocline.
There are a couple of dive/training platforms, attached by a line, which goes on to lead to a bunch of ’bones’ further down.
You enter it via an old boat ramp, which I understand is almost out of the water now, due to the low lake levels (and this has affected the depth of the training platforms as well, I imagine).
There are a couple of dive ops there, if you don’t want to use the ramp. The one thing I also remember was that there seemed to be a constant sound of boat engines overhead. There are usually a few divers in that area, however, the boats still do come in pretty close.