Make a superhero float

I set my children a challenge yesterday to make a superhero figure float as a fun superhero science investigation. The activity itself was easy to set up, almost mess free and kept my three busy for at least an hour as they experimented with different ways to make their figures float.

make a superhero float

Figure from the new DC Superhero Girls Range

What you’ll need

Container to hold water



Materials to test – we used bubble wrap and chopped up pool noodles, but you could test with anything as long as it floats.


We talked a little about why some things float and some items sink, then we thought about why children who can’t swim wear arm bands and how we could give our figure the same buoyancy, then I left the children to test and explore themselves.

These were my arm bands for Spiderman.

spiderman arm bands


My 9 year old chose to make a raft like structure with the pool noodles, but then after seeing my idea made a hole in the centre of a noodle circle and simply pushed the figure inside like a circular float.

superhero invstiagtion

My 5 year old used the bubble wrap to fashion large arm bands.


Why does this happen?

Although the bubble wrap or pool noodle makes the figure weigh a little more, it also displaces more water making the figure more buoyant.

The pockets of air in the bubble wrap and pool noodle mean that the figure and bubble wrap together are less dense than the water, making the figure float.

Extension ideas

Can you make a lemon sink? Think carefully about why the lemon floats to work it out.

Can you think of a liquid that would float on the top of water? this would make a great density jar.

Could you use salt to make the superhero float?

Links to English

Write a superhero story where the hero has to find a super fast way to make him/herself float.

Write a set of instructions so someone else could copy your design.

Links to Maths

Can you time how long it take you to build your design? Do you get faster as you practice? Can you record the same data for other people?

Weigh your superhero figure, does a heavier figure need more of the buoyant material?

Suitable for Early Learning Goal 16

Exploring and using media and materials

They safely use and explore a variety of materials, tools and techniques, experimenting with colour, design, texture, form and function.

Key Stage 1 

Everyday Materials

Uses of Everyday Materials

Working Scientifically



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