Diving Incident : G(r)asping for Air and Logic Underwater

Enroute Diving…

How many times have you decided to drive down to the nearest dive center for a well deserved weekend of diving action after a torturous week at work? That’s exactly what I did during the latter half of last year. The good weather played its part and I was in the dive boat, fully kitted out, before I knew it. The sunny sky, the good visibility, and the glassy sea invited me to think that the day’s diving would be peaceful with the absence of a diving incident.

After the pre-dive briefing and buddy pairing, I mentally recited and rehearsed various emergencies and their respective procedures. I had been paired with another diver, who was undertaking a road trip across the country.

The charted depth of the dive site for our first dive was 27 meters. My friend and I decided that we would commence the ascent after either spending 26 minutes at the bottom or when either of us would be down to 50 bar of air pressure, whichever was earlier. We reckoned that this would give us a safety margin of two minutes and enough reserve in the tank to carry out a safe ascent with a safety stop. I notified the ascent conditions of my buddy pair to the DM, who would be the dive leader for the day’s diving. The boat anchored and we were finally good to go!

Dive Dive Dive!

All divers finally commenced descent and we bottomed out at 26.4 meters – well within planned limits. After touching the bottom and the ‘all okay’ signals, we started exploring the area. Everything was ticking along rather nicely and I was enjoying the tranquility and the beauty of the underwater world.

I made sure that I regularly checked my air pressure and kept my buddy well within my vision. As we were nearing the end of our NDL, one of the pairs of divers motioned that they would be commencing ascent. A quick glance at my dive computer confirmed that we were approaching the 26-minute mark and all of us decided that it was time to head home.

buddy breathing during the diving incidentBizarre Logic coupled with Nerves of Steel makes for a very foolish (wo)man

A subsequent check revealed that I had 110 bar of pressure remaining. My inquiries about my buddies remaining air supply were answered with the ‘all okay’ signal and we subsequently commenced ascent. At the safety stop, my buddy bizarrely motioned to us and indicated an ‘out of air’ situation. Before I could respond, the prompt DM, who was diving side-mount, handed over a spare regulator to my buddy. Unlike my buddy who seemed rather cool about everything, I was veritably miffed, but I decided to let it pass and thought it best to vent out my concerns once on the boat.

We finally embarked the dive boat, and after a few minutes of ‘composure recovery’, I calmly asked my buddy about the incident. He casually mentioned to both me and the DM that he was low on air towards the end of the dive but gave me the all okay sign prior ascent as he had figured that I had enough air to ensure ascent and a full safety stop for the both of us.

We were baffled by his calculations and bizarre line of reasoning; further probing left us even more confused about his logic and with frayed tempers. Although I was not very pleased with the developing situation, I was glad that everybody was safe. Eventually, the DM and I, silently let the matter pass to avoid any unnecessary altercations. I eventually ended up diving with another diver.

My buddies uncanny ability to dive on fast depleting air (or none at all) could have led to a fatal outcome for all divers. An analysis of the incident brings forward the following: –

  • I should have insisted on knowing the exact air pressure my buddy had prior ascent.
  • I had 110 bar remaining prior ascent. A total of five minutes of ascent (including safety stop) and a conservative calculation suggest that I would have had a reserve of 90 bar on breaking the surface. However, with buddy breathing this would have probably reduced to approximately 25 bar or lesser.
  • Luckily, we had two redundancies for one emergency (self and DM’s air supply). In fact, my buddy did not panic underwater thereby avoiding a panicked diver + out of air situation. We were also lucky that the situation evolved near the surface.
  • We failed to plan the dive and dive the plan properly.
  • A safe dive buddy makes the dive 2x safe for you. A dangerous dive buddy makes the dive 5x dangerous for everybody!
  • It highlighted the importance of keeping the emergency drills sharp by regular practice (out of air, lost/displaced mask, lost buddy, CESA, free-flowing regulator, buddy breathing etc.)

Summing up

As I drove back home after my first diving incident with a new story to tell; I wondered whether it would be my last. However, I certainly decided to be a safer and more strict driver that day onwards…

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