Eureka! Watch your very own Cartesian Diver illustrate Archimedes' buoyancy principles as it sinks and resurfaces with this Kit from Great Gizmos.

Simply fill the clear plastic "Diver" with water and place in a bottle of water (we recommend a 2 Litre bottle). Your diver will float at the surface until you squeeze the bottle and the change in pressure makes the Diver magically sink to the bottom!

For added fun a set of plastic weights are inluded with point stickers; involve the whole family and see who can rack up the most points by collecting the most weights. 

Experiment by seeing how slowly you can make the diver sink and float, or try to make it "hover" around the middle of the bottle.

The Cartesian Diver from Great Gizmos is a great toy for young children as well as an excellent demonstration tool in the Secondary level science classroom.