Adult Supervision Required...

Materials
2 liter soda bottle
straw
clay
paper towel
1/2 Tablespoon baking soda
1/4 cup vinegar 

Directions
1. Cut a small hole in the bottom of your soda bottle, and poke the straw half way through.

2. Plug the gap around the straw with clay so that no air can escape out of the bottom of the bottle except through the straw.

3. Place the baking soda in the center of your paper towel, fold it lengthwise and twist the ends closed. This is to protect the baking soda from the vinegar for a few seconds.

4. Pour the vinegar into the bottle, add the paper towel with the baking soda and place the cap on quickly.

5. Put the bottle into water (pool or bathtub) with the straw submerged under the water surface like a motor.

6. As the baking soda and vinegar begin to react, the "boat" will be powered forward!