20 feet under the surface of the ocean, light begins to fade and colors slowly vanish. Red is the first to go.
33 feet under the ocean's surface, pure oxygen becomes toxic under the pressure of 2 atmospheres.
40 feet uder sea level, yellow and orange vanish from the spectrum and your worls begins to look like a black and white silent film.
100 feet below sea level, you might start suffering from nitrogen narcosis.
297 feet under the surface of the ocean, the pressure is now equal to 10 atmospheres and even normal air becomes toxic to breathe.
500 feet and plus below the ocean's surface, the continental shelf drops off into the deep abyss.
1200 feet below sea level, the temperature can go as low as 33 degrees F or 0.5 degrees C. That's right above the level of fresh water freezing.
4500 feet below the surface of the ocean... At four thousand feet below the surface, no light reaches you and hope is a forgotten word. Welcome to the Sub-Attica labor camp... Pray you die quickly.

Sub-Attica is a Cyberpunk ARU sourcebook loaded with information about the dreaded Sub-Attica underwater detention center, with complete layout and full NPC stats. It also contains eight mini-adventures designed to make the player's life miserable.