By Brian Lam - Gizmodo
You think carrying your grocery and laundry into your 5th-floor walkup is a pain in the ass ?
Try bringing that stuff into an undersea base without it getting soaked. How do you do it ?
The answer is surprisingly low-tech: pressure pots.
Pressure pots are paint cans that have been modified with a release valve that lets them gradually normalize to their surroundings' pressure.
When they go down to the habitat, the valves let air flow in slowly, adjusting to an environment that is at 2.5x regular atmospheric pressure; when they come, they let the pressure slowly bleed off.
Clamps or bolts hold the lids on, and divers swim them 50 feet down to the entrance of Aquarius Reef Base.
Without the bleed off valve, a pot would be dangerously compressed when brought to the surface—the lid could literally fly off when you undid the clamps.
When brought down to the bottom, a canister's vacuum would make it impossible to open.