See, I don't understand this.
Many, many planes have gone down in the past, usually in the ocean, but also on land, and have never been recovered. Ships have gone down from time immemorial, there was never an expectation that bodies would be recovered, unless they surfaced on their own.
Clearly, the plane went into the ocean and no one survived. Why is it a 'living nightmare' to know your loved one died in a plane crash in the Indian Ocean? Would having murky underwater photos of what might be a plane make any difference?