[XenonSurf]

Good question from the dev: why using emergency blow?
I'm not a skipper, but my understanding is that it's a very last ressort to get the sub to a depth allowing the crew to abandon the sub alive.
I see no other good purpose, everything else can be done by normal operations.
Also when you are using this desperation move, then the enemy is the last thing you should care about.

In a few videos for the public you usually see such quick surfacings. It's done to make more 'action' for the public, else pictures of subs would be plain boring... But one scene from Red October is quite realistic: vertical evasion, thus getting the sub ''out of the water with big waves", is a consequence of changing depth and surfacing at max. speed to evade torpedos, you lose a significant amount of speed by doing so, so a good skipper would avoid that making the sub stabilize at 50 feet or so before releasing a noisemaker and going down again. In reality it's so that you cannot do that too often in a row for the sake of your crew... What are the effects of going from 800 feet to 50 feet in 2 minutes and this more times? I don't think this ends well...

A sub on the surface is as good as any warship stucked at 0 knots...Both are lost, just zombies...