Even if you don't dive w Divetech, as suggested by Northeastwrecks, you should check out the shore diving at Divetech's Turtle Reef location.
I was in GC junior certifying my son just before thanksgiving, and his first post cert dive was done at Turtle Reef. Of the 10 dives we did that weekend (well long weekend), it was the dive with the richest reef life and color: flounder, turtles, lemon ray, eagle ray, spotted eel, moray, anenomes, small school of big tarpon, lobster, peterson shrimp, all sorts of corals and sponges, and the usual suspects: jacks, angel, parrot and others....and lots of all of it!!! wow! I'm not sure I've ever seen as much in one 56 minute dive as I did on this shore dive... certainly not on the west end of GC. It beat anything else we did that weekend, although the walls and swim thrus at Round Rock and Trinity Caves were quite fun...I did those while he was doing check out dives in the sand flats above these sites.
Whatever you decide you should check out this great shore dive.
Joe