Project: D.I.Y. Submarine – Build Your Own Bath Time Explorer!

Project: D.I.Y. Submarine – Build Your Own Bath Time Explorer!

posted in: Parents, Technology | 0
Print Friendly, PDF & Email

Bath time just became way more fun, because we’re going to show you how to make your very own submarine and find those bath toys lost deep under the bubbles!


Here’s what you’ll need:

  • An empty 2-litre plastic bottle
  • A roll of duct tape
  • Weights to keep the bottle under water – this can be anything that’s safe and water friendly
  • A knife (let a parent look after this!)
  • A rubber tube
  • A bath full of water


Here’s how to make the submarine:

1. Using your knife, cut 4 holes in a row along the side of the bottle (let a parent look after this too!).

2. Place your weights on the same side as the holes and use the duct tape to hold them in place.

3. Remove the bottle cap and use your knife to cut a hole in the top of the cap, just big enough to fit the rubber tube into.

4. Push the rubber tube into the hole you’ve just made and screw the cap back onto the bottle.

5. Place the bottle into the bath with the holes facing the water, then gently unscrew the cap to allow water to enter the bottle until it sinks to the bottom.

6. Screw the cap back tightly and blow air into the free end of the rubber tube.

7. Watch your submarine rise from the deep!


The video below will help you build your super submarine. Experiment with how much air you blow into it and see how far it rises and falls in the water each time! Don’t forget to send us in pictures and videos of your creations! If you’d like to learn more about submarines, take a look at our post on the Science of Submarines.