What you’ll need
- A water tray, bucket or bowl
- A variety of junk modelling boxes, containers, straws, lolly sticks etc
- Waterproof construction materials
- Tape- waterproof if possible
- Photographs of different boats PDF
- The marine engineer poster
Duration
10 minutes or so.
Marine Engineer posterChallenge the children to design and create a boat to float in your water tray.
Early Learning Goal links
- Mathematics ELG: Numerical Patterns
- Understanding the World ELG: Past and Present
- Understanding the World ELG: The Natural World
- Expressive Arts and Design ELG: Creating with Materials
Characteristics of effective learning
Our EYFS units provide enabling environments with teaching and support from adults. Reflecting on the characteristics of effective teaching and learning, children will have opportunity to learn and develop by:
• playing and exploring – children investigate and experience things, and ‘have a go’
• active learning – children concentrate and keep on trying if they encounter difficulties, and enjoy achievements
• creating and thinking critically – children have and develop their own ideas, make links between ideas, and develop strategies for doing things
Taken from Statutory Framework for the Early Years Foundation Stage.
© Crown copyright 2023 licensed under the terms of the Open Government Licence v3.0.
STEM vocabulary to introduce
Float, sink, sunk, sank, rise, rose, risen, size, big, small, heavy, light, bottom, top, surface, under, side, shape, predict, design, test
What to do – step 1
Set up an area in the classroom for the children to design and create their boats. You may want to set this up with specific materials that you know will float and are waterproof, or you may want the children to investigate these properties.
Step 2
Tell the children that marine engineers are creative and design and build vehicles and structures to go in the water. You could show them our marine engineer poster. Show the children or display pictures of marine vehicles in your design and create area. You could print off our photographs of boats. Ask the children to design, build and test something that will float on the water.
If the boat sinks or falls apart in the water, remind the children that marine engineers are curious and want to know what happens. It doesn’t matter if the boat sinks, as long as we have found this out. Remind the children that marine engineers are resilient. If the first boat they try doesn’t float, they can try again.
Questions to ask to support and extend learning
- Which materials will you use to build your boat?
- Why have you chosen these?
- What sort of shape will you build your boat?
- Why do you think this will be best?
- What do you predict will happen when you put your boat into the water?
- Did your boat sink or float?
- Why do you think it sank?
- What could you do to make it float?
Other things to try
Remember to refer to the children as marine engineers and praise them for using the attributes. You could say things like:
“Well done! You have been resilient like a marine engineer and kept trying to make a boat after your first boat sank…”
Adults might want to try making these origami boats.
The science of boats
We have put together some useful information about the science of boats to accompany this activity. Don’t worry this is for your information only and to help you answer any questions children may have. We don’t expect you to explain this to the children in your setting!
Why do some objects sink and some objects float?
There are two forces acting on objects in the water. The weight of the object pulls down, while the upthrust of the water pushes it up. If the weight of the object is equal to, or less than, the upthrust, it floats. Things that float are buoyant. If the weight of the object is greater than the upthrust, the object will sink.
What is upthrust?
This is the upward force pushing towards the surface. When you try to hold a beach ball, empty plastic bottle or inflatable under the water, you can feel this force pushing it towards the surface. The upthrust force is equal to the weight of water displaced by the object.
Why do some materials float then sink (such as paper or sponge)?
Some materials are light because they are full of holes! Sometimes these are holes you can see, like in a sponge, but some are tiny holes that you can’t see, like in paper. The holes are full of air. Air is not heavy enough to push down into the water, and so materials that are full of air, float. When the materials full of air holes are floating, the water starts to fill up the air holes. The water soaks into the material and makes the weight pulling downwards greater than the force of the water pushing upwards.
Which shapes make the best boats?
Objects with a lower density and a greater volume (flatter, weight spread out) displace more water and will float. The shapes in the photograph are make from the same amount of plasticine.
Gravity pulls the plasticine down with a force equal to the weight of the plasticine. While buoyancy force pushes the plasticine upwards with a force equal to the weight of the water that the plasticine displaces. If the clay can displace a volume of water that equals {or is greater} than the weight of the plasticine, then it will be buoyant and float.
With the boat shape, the displaced water is equal to the weight of the plasticine and it floats. With the ball shape, the displaced water weighs less than the weight of the plasticine and it sinks.
