The passengers, along with the cabin of the submersible, are pressurized in the hyperbaric chamber on the support ship at the surface of the ocean. Keeping the people in an environment of approximately 4.5 atmospheres allows them to enter the habitat through the moon pool safely. Likewise, having them pressurized on the way to the surface eliminates the need for pressurization and decompression systems aboard the submersible. The passengers simply undergo decompression in the hyperbaric chamber on the ship.

Cabin air is constantly circulated through the upper two pontoons, where 20 carbon dioxide scrubbers replenish the oxygen supply. Running at 24 VDC with a current of 1 amp, the scrubbers fit snugly into cylinders that span 6.5 meters and have diameters of .30 meters. Like the pontoons in the cabin, these are detachable and interchangeable for shorter delays between consecutive dives. Water removal and temperature control are managed by an environmental conditioning system located at the rear of the vehicle. Auxiliary carbon dioxide scrubbers are located in the passenger cabin, and air can be circulated through them with the aid of a spare motor blower and 12 VDC batteries with capacities of 84 amp hours. In addition, chlorate oxygen generators and oral-nasal masks for each passenger are located under the benches in the cabin for extreme situations.

If oxygen levels drop, oxygen and carbon dioxide monitors will alert the crewmembers to begin using the auxiliary scrubbers. Since the oxygen canisters pose a risk of fire, smoke detectors and hyperbaric fire extinguishers are located in the cabin and storage area. Pressure gauges in the cabin and both inside and outside the conning tower will inform the crew of leaks or sudden changes in air pressure. Hydrogen detectors in the battery pontoons are needed to reduce the risk of a spark igniting the compartment and leak detectors will alert the pilot to punctures in any of the four pontoons.