Make Bath Time Fun- Build a Paddle Boat!

Rubber ducky toys not cutting it? Put your child's mind to work while they create a paddle boat! With this simple engineering STEAM activity, they can learn about different types of energy that can power their paddle boat to move in the water.


  • Plastic Water or Pop Bottle

  • 2 Wooden Chopsticks

  • Plastic Milk Jug

  • Scissors

  • Duct Tape

  • Rubber Band (thicker is better)

  • Ruler

  • Pencil

  • Packing Tape


Use the photos from Coffee Cups and Crayons for reference!

  • The plastic milk jug should be cut into four rectangular pieces that are two (2) by three (3) inches each.

  • Make sure your pieces are straight and level by measuring with your ruler and marking with your pencil before cutting with your scissors. (Remember: Measure twice, cut once!)

  • Any pencil marks left over after cutting can be erased.

  • Make an "L" shape by folding each piece in half.

  • Make a cross by taping the angles together with strips of duct tape. Set aside.

  • Your chopsticks can be attached to either side of your plastic bottle with packing tape, making sure half of the chopstick hangs off the rear.

  • Once you have placed the chopsticks and bottle as you would like, secure them with duct tape.

  • Ensure that the rubber band fits tightly over both ends of the chopsticks, without being too loose.

  • In the end, slide the rubber band through two of the blades from your cross shape to create your paddle. Your new boat will scoot over the water as you rotate its paddle!


To drive the paddles in this experiment, you manually wound the rubber band before placing it in the water, which unwinds the paddles.

By winding the rubber band, you are converting the kinetic energy in your hand into potential energy, which on unwinding is converted into kinetic energy, which in turn causes the paddles to move.

What is kinetic energy?

Kinetic energy is energy that can be turned into motion.

What is potential energy?

Potential energy is stored energy at rest in an object.

Further Exploration

  • Turn the paddle towards the boat to see what happens.

  • Is it any different if the rubber band and paddle are moved closer to the boat? How about further away?

  • Is there a reason why the water moves away from the paddle as the boat turns?

  • Does twisting the paddle make any difference?


Sheakoski, Megan. “STEM FOR KIDS: BUILD A PADDLE BOAT” Coffee Cups and Crayons, Accessed 28 September 2021.

Goolsby, Anna. "Build Your Own Paddle Boat." Adventure Science Center, Accessed 28, September 2021.

"Build A Paddle Boat." Rookie Parenting Science, Accessed 28, September 2021.

9 views0 comments

Recent Posts

See All