Chalk, you're living the legend. When you get about 50 and still do the Ickky, you will be zipping in and out of the river like the old timers (you'll be one of them) and during the process over the years, you will have found every rock there and left a propeller blade here, a whole propeller there, skegs all about and maybe a lower-unit or two here and there.
I've always been a lot more cautious, because after 3 props and 2 skegs, I didn't care to spend any more down-time waiting for parts or lining-up heli-ark welders. I wish you luck at skimming over the tops of those bumps on the tops of those monster limestone slabs. Being a geologist at one time, when I got to Tallahassee and later started to fish the Big Bend area, I spent a little time at Stozier Library at FSU and checked-out the local underlying geologic structure. The general area from about St. Marks to way past the Suwannee is an area of some of the finest-grained limestone in the world. Fine grain means, hard, for limestone. Of course, almost all of the land area is overburdened with sandy soil, but underneath it at various thicknesses is that killer limestone which the streams in the area usually expose. Aucilla and Econfina are the two prime examples of, "bust yo mota" fine-grained limestone outcrops in the area. This limestone is not loose, stream rolled rocks or even stream rolled bolders, they are vast layers of fairly thick limestone ledges with varying bumps and peaks and even big cracks that erode very slowly even under the constant impact of propellers, skegs and lower-units on outboard motors and even boat hulls on occasion! I prefer to gently move among that stuff and try to get along with it. Wave at me as you go scoot by and I'll wave back at ya!
