This vessel is worth a LOT of money
Dear, the submarine world is a harsh one.
The vessel is worth NOTHING anymore. It is now a wreck. And it was not worth much as it was 40y old, probably one of the oldest still in service worldwide.
Now, technically it SHOCKS me that such a small unit, with a usual crew of 34 / 35 took nearly 20 additional people on board, the boat is not designated for it.
Yes in.some "recon" mission a small team of "operators" will be on board, to be infiltrated somewhere.
But in this case, as it was a torpedo shoot exercise, i expect the "visitors" to be cadets, observers etc... But 20 additional staff, unfamiliar with the environment are simply a danger if shit happens and should never be allowed. They will simply panic and will hinder the crew to react to the incident.
Salvage at sea is a big business, but more in the civilian world.
Concerning the crew, as I mentionned and if the boat (a sub is called boat, not ship) sank, further to a incident, (torpedo explosion being the most likely), way beyond its max permissible depth, it will have been crushed by the water pressure on the hull.
en.m.wikipedia.org
If you want have an idea of what this is :
Now, dont think I am heartless, way from it. Submarine fatal accidents happen regulary. Russian Kourks, Chinese, Argentina (above), USA 2 or 3, France lost 2 in the 70's. Japan had a very close call a few months ago, and they were VERY lucky to stay afloat and survive.
Google or Wiki "submarine accidents".