The systems are working as intended and not changing. Thanks

@superosh Over pressure protection added.

@superosh Thanks for the heads up. I am fixing the pressure safety system now. The system is working as intended and I'm not going to do it "the old way" for a number or reasons. The only thing that was not working was the pressure safety system. The sub already will remain at depth. It already subtracts the ballast in the airlock for the tank.

Nice design.
However, the airlock killed my player char.
While flooding the airlock, I checked the fluidi-port, which shows 15 ATMs.
So I switched to god-mode, just to try to empty the airlock again.
This didn't work. The pumps were pumping, but no water went out of the airlock.

Maybe it's better to use the "old" way: (?):
Using ballast tank to flood the airlock.
The air could be passive "pressed" into the main (lower) cabin i.e.
Later on, you could use this additional air to speed-up the air-lock empty-cycle.
Maybe using a variable valve to make sure, not to go to high/low on ATM while pumping in/out.

If using ballast-water to flood the airlock, the sub would remain it's depth, too.
Using external water made the sub sunk to the ground (caused by the additional water in the airlock).

I tested this at 200 m depth (ground contact about 215 m)

😜

Where sink Button?!