This is a floating dock that's easy to make and works beautifully.
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
So once you have your parts head out to the body of water you want to place the dock in. Get as close as you can as your final product will be quite heavy and you don't want to have to move it too far.
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.