Speed of Sound wrote:
As well as what Coagie said it takes proportionately more power to generate and transmit an 11KHz signal than it does a 37.5KHz one, therefore for a given amount of power the 11KHz will be sustained for less total time than the higher one.
I found out that the main reason is the size of the beacon. I'm not sure about the power consumption.
According to
https://fenix.tecnico.ulisboa.pt/dow...651/resumo.pdf
Decreasing the ULB transmitted signal’s frequency. The attenuation losses induced by the Underwater Acoustic Channel (UAC) are highly dependent on frequency, and increase proportionally to its cube. Hence, reducing the current 37.5 kHz to a reasonable 10 kHz has the potential to greatly enhance the maximum depth and range for which the ULB signal can be detected. The downside of this solution is that the physical size of the beacon would have to increase