My transmitter makes an audible noise while diving
The transmitter makes an audible noise when transmitting data over the Subwave™ sonar network during normal operation. Sonar signals are noticeable while diving, and because sound travels better through water than radio waves, the Subwave sonar network has longer range than traditional radio-based products. The Subwave sonar network uses a lower power signal (1 W to 10 W) than traditional marine sonar systems (around 1000 W). Testing has not indicated any disturbance to sea life.
You can decrease the power setting to reduce the audible noise from the transmitter (Adjusting the Transmitter Power Setting).