Interactive
University of Colorado

University of Colorado: Ph Et Interactive Simulations: Fluid Pressure and Flow

For Students 9th - 10th
Explore pressure in the atmosphere and underwater. Reshape a pipe to see how it changes fluid flow speed. Experiment with a leaky water tower to see how the height and water level determine the water trajectory. Java required.
Activity
Science Bob Pflugfelder

Science Bob: Make a Cartesian Diver!

For Students 3rd - 7th
This site presents a procedure for creating a cartesian diver, a miniature submarine which rises or sinks depending upon the water pressure within a closed bottle. The site also introduces basic concepts of water and air pressure.