Oh come on! This is BS!

[Penelope_Grey]

Only thing I can think of is that SOMEHOW they are able to see occasionally my radio antenna out of the water but in REALITY this is pure crap.

If enough of your conning tower was exposed, they would see you rough weather does cause this. During rough weather, you are that close to the surface it is realistically tough to keep a boat level and at right depth. Ideally, and if it was me, I'd have set depth for slightly deeper than periscope depth. For safety reasons.

Also as I understand it from my own experiences, it seems the enemy AI is constantly alert. In GWX the ASW effort is a lot better than in base game. So, these combined, comes with the territory.