Monday, 13 June 2011

Practical difference between knowledge and know-how

About a year ago I was part of a group that was scuba-diving around the Daedalus Reef, smack middle of the Red Sea when something went wrong during a dive. We were down at 31 meters on top of the reef-plateau, close to the long pier when my buddy's regulator malfunctioned and started blowing. As we were the last ones in our group no-one else saw what was happening.

We did everything by the book. I noticed my buddy's problem right away and was able to help her as we had kept close to each other instead of wandering to separate directions as some other diving pairs had done. As we were at the bottom of plateau we settled down on it to see if the situation could be sorted out. There was no panic, no sense of urgency or rushing - we had time.

I gave her my spare regulator while we tried out the few tricks we knew that might stop the regulator from blowing, but none of them worked. The regulator was stuck open and was venting out the tank. As I took my buddy's pressure gauge to see how much air she had left I saw that during those few moments her tank had gone from about 200 bars to well below 100 bars, and the gauge hand was steadily moving towards red zone. There was nothing more to do but to signal ascent and prepare to surface.

Then I fucked up.

As we were still on the bottom of plateau at 31 meters we grabbed each other's BC (buoyancy control) vests and I fed air to my BC to begin our ascent. Her BC was almost empty and she was hanging heavy, so I fed some more air to my BC while keeping my eye on my diving computer's depth and rate of ascent indicators. We were doing alright, rising steadily but slowly enough - until her still blowing regulator ended up between us and all I could see and hear were bubbles. Lots and lots of bubbles.

As the torrent of air was rushing and bubbling around my head I could no longer see my diving computer nor hear its frantic alarms telling me that our ascent has become uncontrolled. Within seconds our slow, controlled ascent had turned to classic two-person cluster-fuck as the air within my vest expanded and accelerated our ascent speed. Once the bubbles blocked my visibility and hearing I lost my situational awareness: I did not know my depth, I did not know how fast we were ascending and indeed the next thing I noticed was how my vest suddenly expanded to its fullest which triggered the vest emergency valve on my shoulder to vent excess air out just as we popped on the surface.

It all took just seconds and afterwards I checked my diving computer's log: we had ascented slowly from 31 meters to about 20 meters, which was when I was blinded by the bubbles. The last log depth entry was at 17.1 meters and less than five seconds later we surfaced. As I signalled the boat crew that we had a problem I knew I had screwed up bad, I just wasn't sure how badly. My mistake had not only put myself in danger but more importantly I might have done some serious harm to my buddy. True, we had come up from 31 meters without safety stop, but on the other hand the dive had only lasted some 6-7 minutes with about 5 minutes of bottom time. Was it long enough for our tissues to collect enough nitrogen to give us the bends?

What did I do wrong? The simplest of things: I forgot to close my buddy's tank valve. She didn't need it any more: she was breathing from my tank and I was the one to control our ascent. If her tank had been closed I would not have been blinded by the blowing regulator and could have controlled the ascent. This was something that was told to me during my dive training and indeed even practiced in the pool, but when theory became practicality I forgot it: it was something I had the knowledge of, but I did not really know. This was the practical difference between theoretical knowledge and experience based know-how.

The same holds true to so many other aspects of life, and to things I have done. Sure, I studied business and IT in the polytechnic for four and half years, and while most of it was interesting and some of it even useful, none of it really prepared me for the realities of practical working life. Everything I know about IT I have learned while doing it, making mistakes and learning from them. Some of the lessons learned have matured to deep understanding that will help me to make the right decisions then and there when the moment so demands - or so I hope. The same could be said about other aspects of life, such as personal relationships (some of the things that my wife appreciates today, I learned from my first girlfriend, usually some time after making a mess of things) and it holds true for my partnership in Envivia as well. Although in all honesty we are still busy with learning from mistakes, but hopefully that, too, will one day mature to success.

What about that diving incident? Well, in the end we were lucky not to show any symptoms of diver's sickness, although the after-treatment didn't exactly go by the book either. After an uncontrolled ascent the first thing to do is to breath 100% oxygen (or richest possible mix of oxygen if 100% is not available). As we we returned to the boat we informed the crew that we need to start with the oxygen treatment right-away, but although there were several O2 tanks on board and even clear instructions by the cabin door, the Egyptian crew could not read English (most of them barely understood spoken English, if at all) nor did they know what to do in this situation. All the diving guides were in the blue with the rest of our group.

About 15 minutes later one of the local guides surfaced once he had noticed that we were missing. Once he came on board we explained what had happened and he gave the crew instructions to prepare for the oxygen treatment. Only problem was that there was only one mask available between the two of us. I chose to wait until my buddy had finished with her oxygen treatment as I had used nitrox during our dive while her tank only had regular air, and I was the one who had made the mistake that put her in danger. Responsibility was mine so she should be treated first.

Afterwards we went over the incident with the guides and decided that since the dive had been so short it should be enough to skip one dive and to go no deeper than 8 meters during our next dive. All went well and I got to enjoy a very good week of Red Sea diving.

However, since that trip there has not been a week that I haven't thought about what happened and the mistake I made. Rest assured that the next time my buddy has a regulator malfunction I will remember to close the tank and exercise proper ascent control - and know how to prepare oxygen mask in case or emergency with  or without the help of the boat crew.


  1. Thanx Mark for that
    PS. Black and white - not so good to my old eyes

  2. Very clear explanation, and interesting. Thanks