Tinfoil Boat Challenge

Goal: Build a boat using only tinfoil that can float and hold as much weight (e.g. coins or marbles) as possible without sinking.

Supplies (per child or team):

• 1 sheet of aluminium foil (approx. 30cm x 30cm)

• A container filled with water (bucket, sink, or large plastic tub)

• Coins, marbles, or small stones for testing weight

• Towels for cleanup (optional)

• Ruler and pen/pencil (optional for design planning)

Steps:

1. Introduce the ChallengeEach child or team will build a boat using only one sheet of tinfoil. The boat must float in water and hold the most weight possible before sinking.

2. Design Time (Optional)Allow 5 minutes for kids to sketch or think about their boat design. Encourage different shapes—flat rafts, folded canoes, or boxy barges.

3. Build the BoatGive each team 10–15 minutes to shape their foil into a boat. Encourage them to think about:

   • How wide or deep it should be

   • How to prevent water from getting in

   • How to balance the weight

4. Float & Test

   • Carefully place the boats in the water.

   • Slowly add coins or marbles one at a time.

   • Count how many it holds before it sinks.

5. Celebrate & Reflect

   • Celebrate creative designs and successful floats!

   • Ask: What made some boats hold more weight than others? What could you change next time?

Other Information:

• Use larger containers if you want to float multiple boats at once.

• If time allows, let children redesign and rebuild based on what they learned.

• Make it a competition, a timed challenge, or a free-play exploration depending on the group.