How Does My Boat Speedometer Work

A speedometer on a boat works by using a pitometer. The pitometer works by comparing how fast your boat is going against the speed of the water you’re travelling on. This works by measuring the speed of water coming into a tube compared to air pressure to give an estimated speed figure.

Where is the speedometer sensor located on a boat?

Your outboard has a water pressure speedometer located on the lower unit of your motor.

How do boats know their speed?

The speedometer on a boat is called a pitometer and it measures the speed of the boat as compared to the water speed. … A tube goes through the hull of the boat and into the water. There are two openings in the tube. One measures the water speed as it moves through the tube, and the other measures the water pressure.