Actually, it's the "Wizard Of All Things Moving" (WOATM) for us, s7rikeback, that's working on that with our two resident sub wizards. All I'm doing is making him some missions so he can see if he can get himself sunk while he watches the testing proceedings... After he gets everything finished, he'll probably hand it all off to cdrsubron7, who is the "Wizard Of Finding All Things Broken" (WOFATB) - gotta have them acronyms, else it ain't "official"... Oh! I also shoot torpedoes at everything he makes, just to make certain they sink. Referring to The Circle Runner vid, I've also managed to sink myself (again)...
As for the state of things, submerged propulsion is an issue... They have solved the invulnerability problem though (get rid of the 'stock' subs)... Everything blows up and sinks nicely.