Reported Story

I am an experienced breath-hold and scuba diver with more than 50 dives under my belt. On the day of the incident I was diving at 20 msw (65 fsw) with a group of friends. We started joking around with each other, as we often do. Whenever I start laughing underwater I take my regulator out of my mouth. This time before I could replace the regulator a friend pushed me from behind, and I laughed more. When I finally replaced my regulator, I was unable to take a breath. I made several attempts to inhale, all of which were unsuccessful. When I tried to alert my friends that I was having a problem, they thought I was joking.

I checked the remaining pressure, and the gauge indicated 80 bar (1,160 psi). I switched to my alternate second stage, but it didn't supply air either. I was too far from my buddies to grab any of their alternate air sources. I pressed the power inflator on my BCD and found that it worked. Despite having adequate pressure, I was unable to breathe.

I decided to swim quickly toward the surface. When I looked to the surface I realized I was not likely to reach it, and the urge to breathe was unbearable. I accepted that surfacing was not an option and did not want to allow myself to panic. As a last attempt at self-rescue, I pressed the purge button on both my primary and secondary regulators. Both expelled air. I placed my primary regulator back in my mouth and pressed the purge button and was able to breathe.

Since it was working again I decided to terminate the dive and made a controlled ascent to the surface. This entire event occurred within 15 to 20 seconds. I am usually very comfortable in the water, but this was a problem I had never anticipated. I had not previously considered pressing the purge button prior to replacing the regulator.


Seldom are dive incidents or accidents due to a single cause. The above case illustrates how multiple factors are involved, and it is fortunate there was a positive outcome. It could have easily ended tragically. In this case several factors should be considered: maintenance of regulators, predive breath test of the spare regulator, buddy diving, underwater communication and joking while underwater.

We know from the diver's account that his primary regulator was working normally and he had sufficient a gas supply. How well the diver maintained his equipment is unknown. Why the regulator did not work properly after removing it from the mouth is unclear, but there can be reasonable speculation. It is possible that debris or salt crystals may have prevented the valve in the second stage to operate normally. It is unknown whether on the surface prior to the dive the diver breathed from the alternate regulator, which also could have been blocked by debris or salt crystals. The negative pressure produced by normal inspiration was likely not sufficient to free the valve in such case. Manually depressing the purge button on both regulators produced sufficient pressure to move the valve. Purging the regulator before returning it back into mouth should be a standard procedure.

Proper maintenance of equipment cannot be overemphasized. Attempting to breathe from both the primary and alternate regulators while on the surface may reveal problems that can be dealt with and avoid a potential catastrophe.

The above recollection reinforces the need for our buddy(s) to be within an appropriate and helpful distance. Buddies who are "within sight of each other" in good visibility may be too far away for assistance when needed. On the other hand, such practice often results in buddy separation. In this case the diver himself stated that his buddies were all too far away for him to reach their alternate second-stage regulators by himself after an attempt of communicating the need failed. A problematic situation can deteriorate in a matter of seconds. DAN data indicate that 40 percent of fatalities involve buddy separation.

Along with proper buddy contact, effective communication is essential. This diver does not report how he tried to communicate his situation to his buddies. His situation, of course, was not the typical scenario that we train for. However, using familiar, accepted hand signals is the best course of action. Reviewing hand signals with your buddy(s) before the dive is important to make sure that both divers understand all signals. It is also an opportunity to review and practice hand signals that are not used often. There is no substitute for proper equipment maintenance, buddy contact and communication.

Above all, it is important to recognize that although a recreation, diving is a serious business; there is not much space for joking while diving.

— Marty McCafferty, EMT-P, DMT