Mix chemistry with sculpture and get learners to create their own boats for this race. Add some weight and discover more of how surface tension works

This experiment may take anything up to an hour, depending on how many “attempts” students have at the circuit. 


  • A plastic washing up bowl
  • Clampstand (no fittings)
  • Cotton
  • Aluminium foil
  • A small piece of soap
  • 10g mass
  • Polystyrene
  • Pins

Health, safety and technical notes

  • Read our standard health and safety guidance here.
  • Wear eye and/or clothing protection if desired.
  • This is an open-ended problem-solving activity, so the guidance given here is necessarily incomplete.
  • As described, there are no significant hazards associated with the experiment. If alterations are made, they should be risk-assessed. 

Possible approaches

The students make a boat from aluminium foil and polystyrene containing a 10 g mass.

A small piece of soap is pinned to the stern (back) of the boat.

The boat is attached to a clampstand in the middle of a plastic washing up bowl of water by a length of cotton.

Students have to see how many circuits of the bowl the boat can make before it needs refuelling.

At least 30 laps of the bowl will be completed on one filling by an experienced “captain”.

Some students will do some major re-designing when they realise that in a washing up bowl, the biggest boat is not the best.

The students will need prompting to replace the water – rather than the soap – for another try. 

Possible extensions

Investigate whether the type of soap makes any difference. Would the boat work in a swimming pool – where chlorine is in the water? 


You will need to change the water after each attempt.