info on this is really hard to search for so I thought I'd try for answeres here.

I am searching around the internet for a kriegsmarine Lt visor cap, and I seem to always come across two types, one with a blue wool top sewn on, with a white cotton removable top over that, or a satin or silk inner lining with a removable,(for the high end ones) white top over it. did the captains use both these types of hats? or is one of them historical incorect? did they wear the one with the wool during winter patrols and switched to the white cloth one during summer patrols? (this would mean I'd have to buy 2 hats now!) and what was the white removable top made of anyway? I saw one pic of a 'origional' hat, white top looked like it was made of some sort of fleese or fancy materal. Honestly, the more I look around, the more and more confused I get, I have almost have no idea any more whats' what. can anyone clarify any of this up for me?