Sitting in a speed boat, my dive buddy and I were looking forward to the dive waiting for us at the end of the somewhat rough ride across the waters around Muscat, Oman. We were headed for Three Sisters,  a popular dive site in the Ad Dimaniyat Islands Nature Reserve.

There were five of us — a young couple, the dive guide and us — entered the water and started the dive. I was wearing dive gear that I had rented from the dive operator. It was agreed that we would follow a coral wall and then turn back based on air consumption. The young couple was consuming air much faster than us and the dive guide signaled us asking if we would like to continue on our own for the rest of the dive. The conditions being perfect and the route easy to follow, we gave an ok.

We continued a few more minutes before turning back to return to the boat. Some 10 minutes before reaching the boat I suddenly realized that I am not getting air even though I had just checked the pressure gauge, which had been reading over 80 bar. Training kicked in and I swam to my buddy to get the octopus before we ascended to the surface in a surprisingly orderly fashion.

On the surface, I had to inflate the BCD by blowing air in it. Neither the octopus nor the normal regulator worked. After a few attempts the air started to flow through the regulator; first intermittently and then in quite a normal fashion.

A few minutes later we had swam to the boat. I told the dive crew what had happened, recommended servicing the faulty regulator set and required a new set for the subsequent dive. I found it a bit unnerving that they did not acknowledge the seriousness of what had happened in any way. I can only hope that this indifference was not due to them feeling that this was business as usual.

In retrospect I have been trying to identify if I could have avoided the whole situation by doing something differently.  Selecting a reputable dive operator and checking the rented gear thoroughly before the dive were not enough this time. Any thoughts anyone?

I never found out what was the root cause of the malfunction but I suspect it was corrosion or dirt in the first stage. While researching the topic I came across of an article that describes a similar experience and a potential explanation: “Weird , Near death causing stuff in regulator!!!”.