I'd like to know why those ships don't attack me.
You could say, that they are buissy with the other (non U-Boat) ships, but that is not the case.
I encountered this several times w/ submarines (over surface) and enemies in two hex-field distance (like in the attached picture), when no other ships were around.
Can't they see me even when being over surface?

... (if I add a picture, the status doesn't say anything. I'm pretty sure I attached a picture years ago ... )
add: From the FAQ:
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