Lowest frequency ones are most effective for deep water and seems lowest operating depth is 6000m which is much deeper than the titanic at ~3500m. see: https://

Lowest frequency ones are most effective for deep water and seems lowest operating depth is 6000m which is much deeper than the titanic at ~3500m. see: https://www.skybrary.aero/articles/underwater-locator-beacon-ulb#:~:text=Low%2Dfrequency%20ULBs,-Low%2Dfrequency%20ULBs&text=The%20maximal%20operational%20depth%20is,both%20salt%20and%20fresh%20water https://www.skybrary.aero/articles/underwater-locator-beacon....