Here is quick parts list of everything I used:
4 - 2x8" pressure treated lumber. 8 feet long.
7 - 2x4" pressure treated lumber. 8 feet long.
17 - 1x6" pressure treated lumber. 8 feet long.
4 - 4x4" pressure treated posts. 8 inches long.
4 - 55gallon plastic Barrels
100ft of Rope
16 - Screw in Eye Hooks
10 to 20 - L shape braces
Galvanized screws and Nails
Here are the parts for the ramp/walkway I added (Step 7)
1- 55gallon plastic Barrel
2 - 2x8" pressure treated lumber. 12 feet long.
2 - 2x8" pressure treated lumber. 3 feet long.
2 - 2x4" pressure treated lumber. 12 feet long.
3 - 2x4" pressure treated lumber. 33 inches long.
4 - Screw in Eye Hooks
6 - L shaped corner braces
1" steel pipe...length depends on water depth.
Step 1: Build the Frame
Luckily I had a relatively flat area near the lake I was placing mine and I could keep things pretty level.
Lay your 2x8 boards out in a square and screw them together. Make sure and keep two sides of the square on the inside of the square effectively making an 8'x8'4" square. I used the pieces of 4x4" posts in the corners as a right angle. I didn't screw these in yet incase I needed to make adjustments.
At this point you can also ready your barrels. Make sure the plugs are tightened and then apply a layer of silicone caulking over the plug to ensure a good seal and prevent leaking. I did not fill the barrels with any sort of ballast but some people suggest doing so for stability. But my final product was quite stable so no worries.