The U.S. Embassy in Port Moresby confirmed this, stating that the hyperbaric decompression chamber located in Port Moresby is currently closed and disabled, with no timeline for when it will be reactivated.
In its simplest form, the hyperbaric chamber is a cylindrical metal or acrylic tube large enough to hold one or more persons and equipped with an access hatch that retains its seal under high pressure. Air, another breathing mixture, or oxygen is pumped in by a compressor or allowed to enter from pressurised tanks.
The chamber is located at the Port Moresby Medical Clinic, but is owned by Hyperbaric Partners Ltd. There is currently a legal dispute between these two entities, and the issue is tied up in the PNG courts.
There are no other decompression chambers located in Papua New Guinea. Should a diver need one, they would have to be flown to Australia on a special medivac plane that can pressurize to sea level.
Thus, the embassy says medical evacuation insurance and diver’s insurance (for decompression treatment) is absolutely required.
(An example of a compression chamber)