Bit of a necro I know, but can somebody answer? Last patrol I tried a down the throat shot at a destroyer, I could see it manually from ~3-4km away, pointed the bloody periscope at the thing and in clear view it's not seen until it's literally 700m away, I may have started yelling insults at my crew because for about a minute I had the periscope pointed at the destroyer steaming at us at 20knots for what felt like a long while and it would not be identified as a target by the crew. I even raised the observation scope too, just to give my crew another view, and pointed it at the destroyer.
