https://phet.colorado.edu/sims/html/under-pressure/latest/under-pressure_en.html

This pressure simulation allows us to investigate the effects air pressure, water pressure, fluid density and gravity on water pressure.

It requires no instruction, it is interactive and entertaining, and allows students to discover properties of pressure. This is a useful tool once students understand the meaning of air pressure and water pressure.

Check the blendspace project for a quiz on this sim.