A Fully Serviced First Stage Gave an Air-Out After 12 Dives

Even servicing cannot prevent failures: buddy breathing is an essential skill.

Reported Story

I am meticulous with maintaining my dive gear. My regulator was serviced strictly according to the recommended intervals from the start. I purchased it in 2012 and in 2016 it was rebuilt. Twenty one successful dives later, I suddenly experience a first-stage air starvation at 60 feet, 40 minutes into the dive. Purging both second stage and octo, and checking the tank valve was open, clearly showed that there was nothing coming out the first stage regulator. I surfaced using my buddy’s air without any incidents. On the boat we tried everything again; there was 1400 psi left in the tank. Reading up I discovered that this was not an isolated incident: similar incidents were experienced by others; all when using a regulator with an automatic closure device (ACD). I have reported this to the regulator manufacture and they provided a response.


We are made aware air-out incidents, at depth, when using a regulator fitted with an ACD. A safety notice was issued in September 2017 by the manufacturer of this specific regulator; evidence of a manufacturing issue. All service shops should be aware of this and know what needs to be done to remedy the situation. The key here is the execution of the emergency action plan with no delay. Equipment can fail; your training and in this case, your buddy should not fail you.

Francois Burman, PE, MSc