My total knowledge regarding submarines is practically 0. I have a (somewhat) technical question that I hope my better qualified fellow readers can answer.

Are there any "distress call devices" which are/could be used in such situations? If not, what would the technical difficulties be, for creating and vertically launching a torpedo equipped with a beacon? If the sub is unable to move and/or broadcast, the beacon would begin transmitting when reaching the surface. I would imagine that launching such a beacon (visual & GPS & ...) would reduce the search area.