Now it's all finished but the platform is floating free and the ramp is somewhat unstable. So I placed poles (not pictured) on the corners of the platform and sunk them as far as I could in to the lake bed. I also placed a few on the ramp to keep it from getting pushed to the side. Just don't make anything too tight, everything needs to be able to move by wind, people walking, water level changes. I've already found the poles make great places to lauch bottle rockets from as well as place tiki torches! (I'll throw a pic of that in soon)
I also attached the platform to the ramp with rope, carabiners and eye hooks. Check out the pic on how I did it. Now it can still be easily detached to float out if need be.
It's not as stable over all as I hoped...if you walk to the far corner of the ramp it dips pretty low in the water and actually rolled the ramp before I added the poles. I guess I could just add 4x4" pillars and take out the barrel........maybe once the water level goes back down to winter levels.