• Bottle of water
  • The plastic ring from under the lid
  • 2 paperclips
  • 1 pen lid
  • Blue tac


  1. Use some blue tac to cover the holes on the pen lid.
  2. Open out one of the paperclips and mould it into a hook, use some more blue tac to secure it to the pen lid.
  3. Fill the botle with water.
  4. Attach the second paperclip to the plastic ring and drop it into the bottle.
  5. Drop your diver in and screw the lid on tightly.
  6. Squeeze the bottle to make the diver move down and release the bottle to let it float to the top again.
  7. See if you can pick up the ring of plastic, or anything else you choose to put into the bottle.
Tip: If your diver isn't strong enough to pick up the object you could try using two. Alternatively it may be that your diver is a little too heavy so try removing some of the blue tac. If it is too difficult to make the diver sink by squeezing the bottle let out a little bit of water as some air at the top can make it easier. If you let out too much water it will be just as difficult. If you are still unable to make the diver sink a smaller bottle might be easier.


Once the blue tac has dried out is can be re-used.