The new underwater labs are fully procedural dungeons that reside on the ocean floor. They will come in a variety of shapes and sizes, and for now, with two entry points. You enter them from a ‘moonpool’ in which you re-surface with your submarine. From there, make sure you have come prepared to face the various puzzles on offer.
This is a companion discussion topic for the original entry at https://rust.facepunch.com/news/going-deep