The giant squid (Architeuthis) and the colossal squid (Mesonychoteuthis) are both believed to live at depths of at least one kilometre (0.6 miles). At this depth, the water pressure is 100 atmospheres – roughly equivalent to having a woman in stilettos walk on every square centimetre (0.2 square inch) of your body! But this pressure is exerted evenly in all directions simultaneously. Squid don’t breath air and they don’t have a swim bladder, so they have no air pockets that could be compressed. The pressure inside their body is the same as that outside, so the two cancel out. The air-breathing sperm whales that prey on giant squid actually have a much harder time of it and can only make brief dives to these massive depths.