Now, I've never lost a dive, so I don't know the exact experience here. However, I've een informed that doing so simply makes you reload a save.
Whilst this is a valid means of handling this, another one would be to have the player returned to enceladus Station, their ship destroyed and their Crew gravely injured, necessitating either flying a new ship, or buying one if none is available- possible having to take out a loan even.
That said, in my opinion, this kind of hardcore mode should be a setting to be enabled at the player's leisure, and should NOT prevent you from loading the save anyways if you feel like it- though a seperate iron-man toggle could also be added to make this impossible.
I'm proposing this because I've had my fair share of close calls, situations where through sheer skill, decision making, or tactics, I managed to make it out just in the nick of time, and having learnt that dying just makes you reload a save kind of feels like it takes away from those achievements - whats the point in just barely making it out if the punishment for not pulling it off is getting to start over?
However, I also understand that this game attracts more casual players and people that maybe don't wanna have to worry about that, hence proposing that this mechanic be added as a toggle, default set to off.