Paddle Boat STEM: Exploring Potential Energy and Boat Propulsion

Paddle Boat STEM Activity: Learning Potential Energy and Boat Propulsion

Welcome to an exciting STEM adventure where we’ll build a paddle boat with a propeller powered by rubber bands! This hands-on activity is designed for elementary-aged kids, providing an engaging introduction to science and engineering concepts. Join us as we explore potential energy and discover how our boat moves in the water.

Materials Required:

  • Recyclable plastic bottle (e.g., water bottle)
  • 2 rubber bands
  • 2 wooden skewers or straws
  • Cardboard or foam board
  • Scissors
  • Tape
  • Pushpin or toothpick
  • Water

Step-by-Step Instructions:

  1. Prepare the Bottle: Cut the plastic bottle in half, creating two separate pieces.
  2. Attach the Skewers: Insert a wooden skewer or straw into each half of the bottle, positioning them near the bottom.
  3. Secure the Skewers: Tape the skewers in place to ensure they remain stable.
  4. Create the Propeller: Cut a small square or rectangular piece of cardboard or foam board.
  5. Attach the Propeller: Push the pushpin or toothpick through the center of the propeller and attach it to the front of one of the skewers.
  6. Add the Rubber Bands: Wrap a rubber band around each skewer, creating a loop that connects the two skewers.
  7. Test the Boat: Place the boat in a container of water and gently twist the rubber bands. Observe how the propeller spins and propels the boat forward.

Exploring Potential Energy:

As you twist the rubber bands, you are storing potential energy in them. When you release the rubber bands, this stored energy is released, causing the propeller to spin and the boat to move. This demonstrates the concept of potential energy being converted into kinetic energy, which is the energy of motion.

Learning about Boat Propulsion:

The spinning propeller creates thrust, which pushes the water backward. This backward force propels the boat forward, demonstrating the principle of Newton’s third law of motion: for every action, there is an equal and opposite reaction.

Additional Exploration:

  • Experiment with different propeller designs and observe how they affect the boat’s movement.
  • Try using different materials for the boat, such as aluminum foil or plastic wrap.
  • Investigate how the size and shape of the boat impact its speed and maneuverability.


Building a paddle boat with a propeller and rubber bands is a fun and educational STEM activity that teaches kids about potential energy, boat propulsion, and engineering principles. By engaging in hands-on experiments, children develop a deeper understanding of scientific concepts and foster their curiosity and creativity.

Share Your Creations:

We encourage you to try this activity and share pictures of your paddle boats with us on social media. Let’s inspire each other and continue exploring the world of STEM together!