Just think how useful a streamed copy of the CVR would have been. How much money would have been saved. How much contentious discussion.
The cost of a charter boat and rescue team pales into insignificance against the cost of implementing what you are suggesting. The data expense alone would be to much to bear for most airlines. Additional to cost you have no guarantee it would even work when you need it. Murphy's Law seems to magically prove itself in aviation time after time.