Saturation diving is a specialized form of commercial diving in which divers live at depth pressure — in pressurized chambers aboard a surface vessel — for extended periods, often weeks, before a controlled decompression brings them back to surface pressure. The Jascon-4 rescue was not a planned saturation operation, but Okene’s sixty-plus hours of air-breathing at four atmospheres produced a level of nitrogen saturation that required the same kind of careful management that planned saturation diving uses.
The diving bell that carried Okene from the wreck to the surface vessel maintained pressure during the ascent — it did not allow the nitrogen-saturated tissues to experience the rapid pressure reduction that would cause bubble formation. The hyperbaric chamber on the surface vessel then provided the controlled environment for the decompression schedule — the staged reduction of pressure over approximately sixty hours that allowed the dissolved nitrogen to diffuse out of the tissues and blood at a rate slow enough to avoid bubble formation.
This two-and-a-half days of additional confinement — in a pressurized chamber aboard a vessel, with controlled conditions — was medically necessary in the same way that the original sixty hours in the air pocket was the result of physical necessity. Okene had no choice about the decompression; his survival depended on it. The chamber was not a precaution or a medical recommendation. It was a requirement imposed by the gas physics of his body.
The experience of the chamber — the specific psychological texture of spending two and a half more days in a pressurized enclosed space after sixty-plus hours in a pressurized enclosed space — is not well-documented in the available reporting. Chamberlain described Okene as “absolutely calm” throughout. Whether this calm was equanimity, exhaustion, or the specific psychological state of someone who had already made peace with confinement is not something the available record clarifies.