the pool. Filmed using the underwater camera housing that I built.
I spent about 50 minutes breathing on the unit, using three pounds of soda-lime CO2 absorbent and less then half of the small O2 tank on my chest in the video. I'm sure I could have easily gone for another hour without surfacing. 20 feet is the maximum depth for this purely oxygen rebreather. The limiting factor is the exposure to pressurized oxygen (1.6 BAR) on the nervous system. Exposure to 1.6 BAR Oxygen (1.6 PPO2) should be limited to 45 minutes, that's why I only stayed down for 50 minutes (wasn't at 1.6 PPO2 the entire time).