CVL (CV?) Visibility Range with Shore Weather

[Taxman66]

Toying around with a Case Blue Scenario.

CVL on the coast of Iceland in a 'shore' hex with snow in a sea area experiencing Clear has 1 hex visibility range. (As expected)
CVL moves into a clear hex and FOW appears to be extended correctly.
HOWEVER there known* subs in FOW, and they are NOT reveled.

*Subs are known to be there since on Axis AI turn they stopped within visibility range of CVL and Maritime Bomber in Iceland which was not experiencing snow on Axis AI turn.

[crispy131313]

Are the subs in silent mode? I thought the purpose of the mode was to be hidden unless a unit was adjacent?

[Taxman66]

I'll check. However, if they are and that is the intent, then why did I see them on the Axis AI turn?