Finally got my Zubmarine and dived. Holy shit, it's drk down there. And I mean literally pitch black. Everything your lamp doesn't illuminate cannot be seen by you unless it has its own light source.
Also,t he enmies down there are
brutal. Most of these enemies are as strong as some of the mini bosses from the surface (the Neath surface, not the real surface). Except enemies with around 500 hp. I think I need a new ship first to make real big dives, my small 75 hp ship won't last long down there.
I like how well they managed the amtopshere. Both the absence of any light and the muffled soundtrack that sounds like you are really underwater, give the game the perfect atmosphere.