Looking at USECs F117 config I've seen that Rocket has put

irtarget = false;
audible = 2; // bigger values easier to hear
camouflage = 0.4; // bigger values easier to detect

All these values mean that the vehicle won't be able to be targeted viar IR radar, and will be difficult to spot or hear. The camo value is only effective when the target is not attacked

If you add values in the cfgweapons or cfgammo (don't remember which one) setting a short distance for the weapons to be detected when fired you will have a ship that will be exceedingly difficult to detect
(I have ported your subs and done this modifications and enemy ships don't fire until you get nearer than 1 klick)

чтобы быть обнаружены при выстреле вы будете иметь корабль, который будет чрезвычайно трудно обнаружить (я портировал ваши подводные лодки и сделать это изменения и корабли противника не стрелять, пока вы не получите ближе 1 Klick)