Eureka! Watch your very own submersible illustrate Archimedes' buoyancy principles as it sinks and resurfaces with this Diving Submarine from Great Gizmos.

Simply fill the chamber with baking soda, place it in water, and watch as your submarine sinks to the bottom of your container, only to resurface again when the wet baking soda gives off Carbon Dioxide, making it lighter than the water and rise to the surface. 

Then, watch in amazement as the gas is used up, and your submarine sinks to the bottom of the glass again.

An excellent toy to teach young children about buoyancy, as well as a fantastic classroom tool for teaching Secondary level children the principles of fluids and density changes.