Pearling ﬂeets, operating in the deep tidal waters off northern Australia, employed Okinawan divers who regularly journeyed to depths of 300 f sw for as long as one hour, two times a day, six days per week, and ten months out of the year.
With higher incidence of surface decompression sickness, as might be expected, the Australians devised a simple, but very effective, in-water recompression procedure. The stricken diver is taken back down to 30 fsw on oxygen for roughly 30 minutes in mild cases, or 60 minutes in severe cases. Increased pressures help to constrict bubbles, while breathing pure oxygen maximizes inert gas washout (elimination).
Similar schedules and procedures have evolved in Hawaii, among diving ﬁshermen [...] Harvesting the oceans for food and proﬁt, Hawaiian divers make beween 8 and 12 dives a day to depths beyond 350fsw.
Consistent with bubble and nucleation theory, these divers make their
deep dive ﬁrst, followed by shallower excursions.
In a broad sense, the ﬁnal shallow dives have been tagged as prolonged safety stops.