That damn aircon

Back in 2015, when I was running a dive resort in the Philippines, we had one weekend off work every month. We took the opportunity to get off the island and spend time in “the city.”

Hotel, mall, cappuccino, croissants, bookstores… and air conditioning. A little bit of luxury, once a month.

While we knew not to set the aircon colder than about 4 °C below the outdoor temperature, over there it had only one setting:  “F”,  for freezer. Every time you stepped outside, you were immediately engulfed in a soggy blanket of 30+ degree, humid air. Stepping back inside felt like getting hit with an ice brick.

Every time we returned from our weekend, I had a cold for a day.

Recovered. More or less

Usually I’d ignore the cold and go right back into the water to guide dives, teach courses, or take pictures. I’d sniff up a good amount of salt water before the dive, gag, spit and/or blow it out again, and my sinuses would be clear enough… kind of.

Not this time. I was completely stuck up until Wednesday. Only on Thursday did things open up enough for me to take my sniff of salt water. And I desperately wanted to go. I had been out of the water for nearly a week, which felt almost unimaginable at the time.

Since I didn’t have any courses lined up and our guide was leading the dives, I was happy to tag along with the customers.

Sweet euphoria

As a dive professional, I of course knew about nitrogen narcosis. That is, I knew of it theoretically, but I had never before consciously experienced it myself. Even below 40 meters on compressed air, I’d never felt a thing. This isn’t to say I wasn’t narked – that would be unrealistic – but I didn’t feel it.

And it didn’t occur to me for a single moment I would experience it that day. I never saw it coming, even though I should have considered it a possibility, with the fading cold still lingering in my head.

While the guide was leading the group, I signaled to him I would take a quick trip down the slope. I wanted to go down to around 25-26 meters, from where I could still see everyone. I’d always found that slope fascinating. On the sandy, gritty bottom with only a few lonely corals scattered about, there were always some funky critters to observe.

At 18 meters, my nose started having trouble staying open, and I got a bit heavy in my head. I pulled off the mask, blew my nose in the water,  replaced and cleared the mask, and voilàá: I was feeling fine.

More than fine, actually. Breathing was easy as ever, maybe easier. The visibility seemed to have improved. And I felt giddy. If it hadn’t been for the regulator in my mouth, I swear I would’ve grinned from ear to ear.

Everything looked more colourful, even the sandy, gritty bottom,  and especially that big triggerfish digging away in its nest way further down. It definitely required closer investigation.

So down I went, straight to the triggerfish.

It was sooo nice.

And soooo big!

And soooo pettable.

Arno Enzerink / www.arno.photography

Wake-up call

On the way down to the triggerfish, it was like I’d stepped out of my physical self. It sounds a bit woowoo, but that’s what the narcosis felt like. I was having a form of hallucination.

Watching from a few meters above, I saw myself gliding off into the distance. Then I suddenly realized what was going on, and I think that was extremely lucky. I snapped back into myself, and the hallucination was over. My dive computer told me I was at 37 meters and had only two minutes of NDL left.

The triggerfish was five meters ahead, slowly turning towards me, trigger up.

For a number of reasons, it was time to head back up, which I did as quickly as my dive computer allowed me. I still had 120 bar left, so no immediate concern there. While I still felt light-headed, there was also a profound realization that I’d had a close encounter with the other side. And with that came a brief, intense moment of panic.

The swim back from 37 meters up the slope to 18 meters took me about 7 minutes. When I got to 18 meters my SPG was showing 60 bar. Never before or ever after have I used this much gas in such a short time.

I found the group and signaled that I would go straight to the safety stop and wait on the boat.

Hindsight, 20/20

Afterwards, I of course recognized the symptoms, and I was able to think through my experience of narcosis, from start until  I ─ thankfully ─ realized what was going on and turned around just in time.

I realize how lucky I’d been.

Sure, I’ve been back to 30+ meters since. But not while recovering from a cold. I’m sitting it out now until I feel good.

There is no fixed depth for nitrogen narcosis. There’s no hard rule that it only kicks in below 30 meters, or anything like that.

In my case above, disorientation began at around 22-23 meters. Even though I was eventually able to equalize, I was still fatigued from the cold, and  a bit of hypercapnia may have added to the nitrogen narcosis.

I have no real memory of drifting down to 37 meters, until I snapped back into it.

Arno Enzerink / www.arno.photography

My personal takeaway

Another thing I realized in hindsight was that I let my status as a professional diver cloud my judgment. In beginner training, we’re all taught not to forcefully equalize, because it can cause damage to the ears. 
We’re all taught not to dive with a cold, because blocked sinuses can prevent you from equalizing – on the way down or up.

I’d done so many dives. Nothing had ever gone wrong. Over time, I’d given myself some leeway to bend the rules here and there. That came to bite me in the backside. Experience doesn’t change the laws of physics or physiology.

There are many factors which can cause nitrogen narcosis to set in earlier than usual. Did you sleep properly the night before, or are you tired? Did you drink alcohol? Are you still recovering from an illness?

These questions are worth considering before you going down. And if you’re unsure if you’re well, don’t be afraid to call the dive.

For your own safety, and the safety of those you dive with.