Also, I too find it rather baffling that a 20 foot Great White can be tracked to the nearest metre and that a plane can't, even in the event of catastrophic break-up.
I think some basic googling will help you there.
Happy for someone to provide some corrections , but I think you will find they only send data when the tag pops off, or the shark is at or near the surface.
Again electromagnetic waves don't go so well under water. (frequency dependence aside)
There are all sort sof 'add ons" that could be made to aircraft to enhance the "findability" in case of circumstances such as this. But it comes down to a cost analysis of what actual advantage you get in the rare circumstances that these things happen versus the pain in the @rse of setting them up.