A Cartesian diver can be used to measure the surface tension of a liquid to a certain extent. The surface tension measurement is related to the two critical pressures at which the diver is about to sink and about to emerge. After sinking because of increasing pressure, the diver is repulsed to the centre of the vessel. After the pressure is reduced, the diver is attracted to the side of the vessel. This phenomenon is known as the "Cheerios effect". Creation of both the repulsive and the attractive phases of the Cheerios effect is feasible by changing the external pressure of the vessel.