[img]http://unknownworlds.com/subnautica/files/2014/09/Flod360.jpg[/img] As the water level rises, there is less and less room to breath. Watch a submarine flood and sink: https://www.youtube.com/watch?v=GukID8fcN_M Submarines in Subnautica might be damaged by collisions, malfuntions, or over-eager large alien lifeforms. In the race to repair a damaged submarine, you are not just trying to stay afloat, you are also trying to breath. This is a technical demonstration of a development prototype. It is not representative of the quality of the final game.