Narcosis is very real!

Contributed by Tod

This event took place a number of years ago while diving with a few mates on a charter in Tassie. We had planned to dive the famous kelp forests in EagleHawk Bay, Tasmania and a wall dive recommended by the skipper/guide. Most of the guys had an early night, smart move, considering the early start we had leaving Hobart at the crack of dawn. We snoozed on the bus and arrived at the dive shop an hour or so later.We packed our gear into the boat and settled in for a cold lumpy run out to the 1st site.

It should be noted that is June 1999. Middle of winter in Tassie. Damn cold. Arctic gale winds and we were told water temp was around 9 degrees in a warm spot. We geared up, briefed up and got into the water. No amount of swear words can describe how damn cold it was, nor can it describe the feeling you have when looking at the one guy in a dry suit. As soon as we left the surface he was signalling by fanning himself as if he was hot...Bastard. The dive
was planned to mid 30 metres. We dropped down and began to explore the wall finding all sorts of great stuff. Big fat lobsters were the highlight.

We were all pretty tight and acted more as a buddy group of four, even though we had officially paired up. I had dived with 2 of the 3 guys before but not the guy I was buddied up with that day. He was fairly new to diving and I was the most experienced so I decided to look after him.

After about 10 minutes I noticed my buddy was approaching the limit of visibility, about 15 metres, but was still at our depth. I started to make my way over to him to see what he had found. As I approached him I noticed that he was descending quite rapidly but he was conscious and swimming around. He seemed to glance over at me,then flipped over and began to swim down the wall. This was a couple of hundred metres of drop off and I wasn't sure where he was going. His range was opening, down. I increased my finning and clutched my hands infront of me looking at my wrist mount computer and my dive watch , both reading 45 metres and dropping. My buddy was still facing down and was finning. We all know that air gets a little thin and sometimes toxic below 40 , I had been to 50 and a bit before but with a pony and a deco plan, so I was a little concerned. I made a snap decision which seemed to take ages but in reality took about 5 seconds.

If I didn't reach him by 55 metres he was on his own. I had already been diving at 30m for about 10-15 minutes so my cylinder was a little light, and so was his. I was not going to make 2 casualties out of 1. So, I kicked like hell with my head down and arms out. I was going to be close. I got hold of him and swung him around to look at me. His eyes very wide open and pupils were like desert bowls. He seemed to be looking through me or past me with no comprehension. I gave him the "ok" symbol and the thumbs up and got a weak nod from him (my computer profile was an almost vertical line from 35 to 57 metres). I began to kick up and he wasn't helping and he was still looking a bit dazed. I put a bit of air into my BC to give us a bit of buoyancy. I know that's not the done thing; but at between 50 and 30 metres the air in the BC doesn't do much and had I not done it we were going to be 60 or 70 metres.

We began to ascend and my heart rate started to drop below 200 beats per minute. I checked our air and was happy with our depth. By the mid 30's he seems to sober up almost instantly, he shook his head like he was in a day dream and he gave me the ok. I let go of his BC but kept him close. I gave him the thumbs up and we headed up. We were way low on air with both of us in the red. My computer didn't have me going into stops but we were stopping that was for sure. My mind was still racing after our little toy with depth, narcosis and cheating serious injury or death. I know we had not taken too much nitrogen onboard, ok maybe he had, it was the same amount as if we had stayed at 30 metres for another 10-15 minutes like the other guys. I was more concerned about how quick we had sucked down our cylinders and some of it was at 5 or 6 atmospheres. I needed more air for this stop, I wanted to do at least 15 minutes at 5 metres.

As we ascended, very slowly, I took out my slate and wrote " went a bit deep, doing a stop, pass down spare cylinder and regs", I tied it to the top of my safety sausage and sent it up when I saw the hull of the boat. We were going up the mooring line so a sausage would have been a surprise to the guy on the boat. I hoped. My buddy had about 40 bar and I was on about 20 when the spare set came down and we happily stayed down for another 15 minutes. The other guys came up and saw us swinging off a deco stop shivering like crazy. Hard to explain all that underwater. We got out of the water and into some warm gear and decided the second dive wasn't a good plan.

We shared the demand regulator on the boats O2 cylinder and tried to explain the event to the other guys and the skipper on the way back to shore. I don't know what the moral to this story is. My buddy was a pretty fresh OW diver so 30 metres probably wasn't the place for him. The water was damn cold which doesn't help with DCI or Narcosis so we should have been a little more aware of that.

I am now a DM and soon will be an instructor and I push the buddy system to my student till it hurts. It's not just in case you run out of air, if you aren't monitoring your air then maybe your shouldn't be down there. Its more for backing up your buddy, in case something goes wrong. If he gets into trouble, you shouldn't be too far away. I always say " How far can your swim if you exhale and then find you are out of air?" Because that's how far you should be from your buddy. Nitrogen Narcosis affect everyone differently and doesn't affect some people at all. If it was constant like DCI then we would have tables for it. So people should be aware of it. Do your advanced course, do the Deep Specialty. I know its more money but its better to find out you have an intolerance for it in controlled conditions rather than on a bottomless drop off.

Keep it safe, it's more fun that way.