IMHO the additional u-boat textures are the only items so far worth to be unlocked. If you should decide to do so, and you got the items, don't forget to rename or save and delete the files r2.rw, r3.rw and r4.rw in the Silent Hunter 5\data folder afterwards, or you might run into troubles for reasons extensively depicted in this thread.

Okay. So I do not have to download new missions with Queen Mary and Ark Royal from Uplay.

I have not even one of the ships in museum in SH5. I really want them in my campaign.

What shall I do please? Step by step instruction please. But I would need a reasonable solution to protect my game by the possible next patch. I don´t want to have problems with played campaign!

Josef, you've got PM. Hope, it helps.