The user guide contains explanation regarding specifications, speed transducer, speed, and transducers. Many info about ultrasonic speed transducer, ultrasonic, speed measurement, and ultrasonic speed are described inside the user guide.
In this user guide you can find explanation such as transducer, installation, sensor, and speed sensor. Below are taken from the user guide:
The Ultrasonic Speed Sensor offers highly accurate boat speed measurement with a minimum of maintenance due to not having any moving parts. The Ultrasonic Speed Sensor uses ultrasonic pulses to obtain echoes from particles in the water. If the sensor loses contact with the water, or is positioned in a flow of highly aerated water, it will lose its signal and register an incorrect speed measurement. Once good water contact is re-established, boat speed is recovered instantly.
Additionally, the user guide presents information such as the ultrasonic speed, ultrasonic speed sensor, and maintenance.