FBW
I'm not sure if I am one of the "guys who always know better" but on two occasions I have been in the position of being able to help the SAR assets communicate when they have had technical problems (usually the HF) and being at low level are out of VHF range.
Having a very accurate starting point for the SAR services to start from has to be a major advantage during a search, an aircraft can glide a long way from 2000 ft and it is a very big sea when you are looking for a guy who is up to his neck in water, with all the airliners monitoring 121.5 this very accurate ditching position becomes available far beyond the range of the land based VHF triangulation system.