A boat's impeller is a small, flexible rubber device with blades (vanes) that rotates in a pump housing to pull water into the engine's cooling system and keep it cool.
The impeller's rotation creates suction that draws water into the pump. As the impeller rotates, the vanes open to draw in water and close to push it.
The impeller blades turn the water into a high-pressure, high-velocity stream that cools the engine by pushing in fresh water and pumping out heated water.
Most impellers should never be run dry and always need to operate with a liquid. It only takes a very short time for them to disintegrate running dry. However Globe's Self-Lubricating Run-Dry® Pump Impellers, can run-dry for 15 minutes. That can make all the difference in an emergency.
