Guards make sure each bather spends the required 15 minutes in complete darkness, as the steel trap doors shut out all light after a dozen or so club members are tossed in. As the amount of available air in the topmost space will only last 1 person 10 minutes, bathers must dive to find the deeper air-pockets, while avoiding the blind carnivorous mutant piranha/squids who swarm up thickly from the deep whenever they detect warmth or movement. The situation becomes increasingly competitive as the abominable fish become blood-crazed and the air pockets fill with poisonous CO2. May the fittest man win!
