Float a Boat STEM Challenges

These simple boat themed STEM challenges are easy, fun and great for all ages.

The challenges work brilliantly for older children who can use them to practise setting up an investigation correctly and can be simplified for younger children who might like a pirate or underwater theme!

Choose a challenge, design and build your boats and then start testing!

Older children can experiment with motors ( remember to cover the battery to keep it dry ). While younger children might find foil or recycled boats easier to make.

Boat STEM Challenge Investigation Ideas

These obviously depend on the type of boat you’ve made, but are a good starting point for any investigation.

Boat STEM Challenge 1

Does the boat float? Fill a container of water and test to see if the boats float. If they don’t float try adding corks or long balloons to the bottle or change the shape.

Boat Challenge 2

How many coins/small figures can the boat hold?

A simple twist to this challenge is to add the coins to one end then all in the middle and then spread them out.

Boat Challenge 3

How long does the boat take to cover a set distance?

You’ll need a boat with power for this challenge. The elastic band powered boat is probably the easiest to make and use.

FLOAT A boat STEM challenge infographic showing three different challenges for a boat themed STEM activity

Build a Boat STEM Challenge

1. Mini Motorised Boats

This mini motorised boat is a great STEM challenge that kept us busy for hours!! We spent a lot of time tweaking the boat to get the balance even and the motor in the right place and then added the balloons underneath for extra buoyancy.

2. Fruity Boats

This is a brilliant science challenge for younger children as lemon boats are easy to make and a good size for adding small figures and other items.

As an extension task, children can try to blow the boats across water with a straw.

Fruity boats - water table science for kids

3. Recycled Boats

Recycled boats are fun to make and great for exploring the concept of buoyancy or as a very simple sink or float activity for little ones. Raid the recycle bin and get started!

boats made from recycled material and lemon skin

4. Elastic Band Powered Boat

This little boat uses the energy stored in a twisted elastic band to spin a section of craft stick which pushes the boat through the water. How fast can you make an elastic powered boat travel?

5. How many coins to sink a boat?

This mini boat challenge is one of my favourites. The aim is to find out how many coins it takes to sink a boat made from kitchen foil. If you want to add an extra challenge, clean the coins with vinegar first!

6. Baking Soda Powered Boat

Baking soda-powered boats are a bit tricky to make but definitely worth the effort. They’re powered by carbon dioxide gas, which is released when baking soda and vinegar inside the bottle react together. The gas is forced to escape from the straw pipe on the back of the bottle, pushing the boat along.