When diving below 20m and rising up again the diver takes no disadvantages from being too fast. There should be some sort of penalty when going to the surface after being below 20m.
Also, the diver lacks a device to see his depth. you have no clue at which depth you are diving.
Dive as a diver deep down and rise up quickly.
To do so, look for a spot near the "map-border" in the editor.
Notice that there is no blurred screen or health-loss during the quick rising, nor the diver performs pressure-adjustements (should be hearable as a crackling noise, gun should lower to have one hand free for the nose, etc.).
When the diving intoxication is being adressed,we definately need a device for measuring the depth.