In years 1985 to 1989 I and my wife Grazia worked as instructors and dive masters at Maldives, in resorts run by Club Vacanze, at the time the largest Italian tour operator, running at least 4 resorts simultaneosly (Buduhiti, Kudahiti, Alimatha and Diggiri, then also Gangehi), and one the first diving ships (Fatuhul-Bari).
At that time there were no strict regulations. We were both certified for a maximum depth with air of 50m, with deco, something that at the time was still considered fully recreative. So we were allowed to bring also our customers to these depths and to make typically 2 deco stops (very seldom 3). Everything was organized for this, decompression cylinders were made available hanging down a bar suspended below buoys, which was deployed from the Dhoni when the dive master was releasing the inflatable buoy at a depth of 9 meters.
It was normal to make 20-30 minutes of deco stops.
Customers were expecting to do such kind of deep and long dives.
There was no Nitrox at the time, but we had pure oxygen on the boat (for emergency) and a full size decompression chamber in each of Club Vacanze's resorts, and a permanent hyperbaric physician resident at the resort.
This allowed to make routinely diving in some very nice deep spots, the better of which were two passes (kandu, in Divehi language): Diggiri Kandu and Rakidu Kandu. Both were with the bottom inside the pass around 46-48 meters, and in Diggiri there were nice caverns just below the step, at 52-56 meters.
With current regulations, no one can dive there anymore, and this is really a pity, in my opinion. So I am strongly in favour of making this possible again. As 30 years ago we were doing this easily and safely using just a single cylinder of air, I do not see a real need for using complex gas mixtures or rebreathers.
But I am generally against limits, so if people accept the higher costs and complexity of these devices, let's allow also them...