Make a mini raft

You’ll need

A small plastic container, such as a butter or Margerine tub
4 thick elastic bands
2 empty, clean 330ml aluminium drinks cans
Sticky tack
Sticky tape
Screwdriver or bradawl
1 cocktail stick
Paper
Towels
Paddling pool or tub, filled with cold water (optional)
Hole punch (optional)

Before you begin

Use the safety checklist to help you plan and risk assess your activity. Additional help to carry out your risk assessment, including examples can be found here. Don’t forget to make sure all young people and adults involved in the activity know how to take part safely.
Make sure you’ll have enough adult helpers. You may need some parents and carers to help if you’re short on helpers.

Run the activity:

Gather everyone together in a circle. Ask everyone if they’ve heard of buoyancy and if anyone knows what it means.
Explain that when an object’s in water, there are two forces acting on it. One is the object’s weight pushing down and the other is the force of the water pushing up, called the upthrust. If the object’s weight is equal to or less than the upthrust, it floats. Things that float are buoyant. If the object’s weight is greater than the upthrust, it sinks.
Tell everyone that they’re going to make a mini raft, then see what floats and sinks.
Ask everyone to get into pairs and ask each pair collect everything they need to make the raft.
First, someone should carefully pierce holes at the top of the tub. There should be four holes created at the top of the tub using screwdriver or bradawl. They should be along the longest edges of the tub, with one in the bottom right, bottom left, top right, top left, just like where you’d place wheel on the car. Make sure you carefully pierce the holes, keeping any hands or body parts holding the tub away from the screwdriver being used to pierce. The screwdriver can be pushed through the tub into a secure, safe object, such as a wooden chopping board.
Depending on the thickness of the plastic tub, you may be able to use a hole punch to create a hole in the sides of the tub safely.
Next, thread an elastic band through each hole and tie each one to secure it in place.
Then, carefully attach a 330ml drinks can to each side of the tub. Use the two elastic bands on each side to secure it in place, then repeat for the other 330ml drinks can.
Finally, draw a flag design onto paper. Carefully cut it out and attach it to the cocktail stick using sticky tape. You may want to fold it in half around the cocktail stick.
Put a small amount sticky tack inside the tub, then place the cocktail stick into the sticky tack to help it stand up.
When everyone’s ready, fill a tub or paddling pool with water and put it to one side of your meeting place. You could also place it outside. You should put towels underneath it to help prevent any spills, and make sure an adult or young leader is always supervising it.
People can now test out their raft in the bucket of water to see if it floats. You could race the rafts by blowing on them to help them move forward.
Next, test the rafts to see what or how many different weighted items can be placed inside the raft and whether it remains floating.

Reflection

This activity helped everyone to solve problems and learn new skills. What was it like making the raft? How hard or easy was it, and what were the hardest or easiest parts? How did you work together as a team and help each other to make the raft? Did you have any problems and what were they?

We had to find items that floated or sunk. Did your raft float or sink? Did you place items in it? What floated and what sunk? Did anything surprise you? Did you enjoy testing out your raft?

If you were going to make a bigger raft, such as one to carry a person, what materials would you use? You could use logs and rope to make the for the base, then use empty barrels to help make it float.

This activity helps us to learn new skills by making use of materials that we would normally throw away or recycle. Why do you think it’s important we try to recycle or upcycle these materials? How can we make sure these items can still be recycled or upcycled once we’ve used them? Can you think of other ways to make a mini raft?

Safety

All activities must be safely managed. You must complete a thorough risk assessment and take appropriate steps to reduce risk. Use the safety checklist to help you plan and risk assess your activity. Always get approval for the activity, and have suitable supervision and an InTouch process.

Make it accessible

All Scout activities should be inclusive and accessible.