(Updated 29.11.2020; re-edit of the hatches chapter) Surely one of the most complicated area of an underwater structure for human occupation is the habitat entrance. It is the local water-air interface, vulnerable to changes in pressure by tidal movements on the surface of the sea; its hatches have to bare potential pressure differences between the habitat interior and the surrounding water; no object that is only a little bigger than the greatest diameter of the entrance can be brought into the habitat. It is constantly wet and humid and the only gateway for medical assistance. But to see in detail let’s have a look at the different sections of the entrance complex. Continue reading “Habitat Entrance”