My parent's cabin does not have drinkable tap water, so we use a lot of water bottles, juice bottles and all kind of bottles (my father prefers beer bottles). There is also no recycling system in this area, so we have to bring all these containers back home. I found a way to reuse them (using only my father's tool box) by turning them into a useful, good looking and entertaining buoy for the lake. They can be used as seats for exhausted swimmers, anchor for your kayak or rock warning... It is also really fun to try to run on them like in a Japanese game show...

p.s. Read the comments to learn how to make it a floating tray, a lantern, a water distiller, an electricity generator (solar or wave motion), a clock, a raft, a floating island, a fishing rope...

Thanks for all your great ideas, Jeff-O, iSmack, Btop and all the others.

Step 1: What You Need

You will need:

-A board of wood or plastic at least 0.5 inch thick (no fiberboard)
-A saw
-A plastic rope
-A lighter
-A knife
-16 Pan Head screws
-16 water bottles and their caps
-Paint (the color you want)
-A piece of flexible foam (1/2 inch thick and more), like a square of Play Mat (I took my little sister's)
-Teflon tape or silicone tube (optional)
-A drill
-A hot glue gun

Step 2: Step 1

With a drill or a punch, make a hole (the size of your screw in the middle of the HDPE caps.

p.s Do not use a nail, it would stretch the plastic.

Step 3: Step 2

Cut a circle in your board. The diameter should be about the size of your foot. If you don't have feet, (sorry) make that 12 inches. You can sand or cut 16 equal flat surfaces around the circumference. Drill a hole in the middle, the size of your rope.

Step 4: Be Precise

Make sure to mark your board correctly

Step 5: Step 3

Drill 16 holes at equal distance. Make sure the drill is in line with the center of the circle.

Step 6: Step 4

Screw the caps to the center piece. (Adding a drop of silicone in the midle of the hole will it make is water tight longer)

Step 7: Step 5

Paint it!

Step 8: Step 6

Cut an 11 inch circle in the foam board. Make a hole in the middle (two times the size of your rope).

Step 9: Step 7

Glue the foam on the board. (Perfectly centered please)

Step 10: Step 8

Make a tight knot in the rope after passing it through the hole. Melt the strings together (do NOT breathe the fumes).

Step 11: Step 9

Adjust the length of the rope depending on where you decided to anchor the buoy. Tie the other end to something heavy but easy to carry (like a bike lock that lost its key).

Step 12: Step 10

Screw the 16 bottles to the center piece, adding silicone or Teflon tape if you notice any leak, and you got a wonderful multipurpose BUOY. Once you finished and tested the first one, you can keep saving your bottles to make new ones varying in size, shape and colour.