We don't seem to have a thread on Subnautica, the next title from Unknown Worlds, the developers of Natural Selection.
They have a new video showing some of how the player's sub may fill with water. It's early in development, but it looks appropriately wet.
There's a spot on Steam for it, but you can't order just yet. I'm looking forward to this. I've wanted a good underwater exploration game for a long time. FarSky didn't quite cut it. World of Diving looks good, but I don't want an MP-only game.