The Amphibious Bottle rolls by rubber band power over water, tub, pool, puddles, lakes.
Just roll it away on the ground like a bowling ball to wind it up.
Step 1: Make first hole
Use a 2 quart round plastic bottle.
Big 2 quart round Gatorade bottles work great.
Drill a hole in the center of the bottom of the bottle.
Any size drill you have handy from 1/4 inch to 1/8 inch is fine.
You can even use a soldering iron to melt a hole in the bottle.
Wear safety goggles.
Work on a proper workbench, not your kitchen counter like I did.