I start my underwater adventure. I visited secret dungeon in New Kiev. Lately I found underwater cave in my Dwellings with some strange "vault doors". I can opened it (I try to interact with the stone/rock formation on both side). Can anybody give me some hint what to do?
Another question: how can I stay underwater longer? I hear some gossip about oxygane tank, but didnt found it.
In exchange I can give some hint about underwater dungeon in New Kiev and another place I already found (underwater).