Shore defense engagement range...
 

I am playing SH5 w/TWoS mod (amazing mod!). I have noticed that the shore defense batteries have a visual range of ~13km against a surfaced sub running at speed. I'm curious, at what range are they likely to start shooting? Is their max engagement range the same as their visual range, or something less? Logically, I expect that in the opening Baltic campaign they might be less likely to engage on sight than further into the war. I've looked around, but haven't found any info about this.

Mucho thankso,
Hegemony Cricket

You can generally see these turrets before they start to fire so you can turn around. A single hit can make massive damage to your sub, do not gamble but turn around. Plot a circle from the turret towards your position so you know you don't get too close.

To my experience, if you get at 2/3 spotting range they will start to fire, but I would have to consult the sim file to be sure which I won't do because I don't want to have the game spoiled for me... Realistically these ranges should vary, also with visibility, and human observations do not have a constant value. But I highly doubt this is simulated as such.