The lack of emergency beacon is the real WTF. Not even an inflatable buoy. Using a game pad is probably OK. But no emergency method to mark their last location or even surface?
Seeing that everything stopped at once, I'd bet that is exactly what happened.
Shades of the Thresher disaster. No doubt we'll hear a few months down the track that the Navy's sound receivers did actually pick up the implosion noise.
There was some speculation that any sort of implosion would've been detected by military sonar, and it hasn't been yet. I do not know if that's accurate -- just repeating what I've heard.
why does it need to be off the shelf, their submarine is not off the shelf. If off the shelf stuff odbly does 200 ATM, then limit your depth or mame custom ones.