SH3 1.4b/GWX 1.03
So far, I have been doing submerged attack practice runs and have a fair feeling for how detectable I am.
I decided to research detection under night conditions with a custom mission and the stealth meter. Here I approach a Tribal Destroyer at 3KTS decks awash (7M); calm seas. As you can see, I am quite literally invisible. I have approached within 100M and only a love tap from the flak gun will get its crew's attention. Until radar makes its appearance, I imagine this is going to have nasty consequences for convoys.
Submerged they can pick me up around 1000M in calm seas. Awash I am a ghost ship. This means that I can strike with impunity. Even if everyone is armed, it doesn't matter if they cannot see me. I can dive to escape after attack. However, it is more likely that I can simply creep off until I break 3000M. At which point, I can right up 18KTS and pull away rearm.
It's going to be a turkey shoot.
Screenshot from the awash test.