Still at Sha'ab Abu Nuhâs reef, I did the Deep dive before breakfast, with our small "class" on a sandy patch next to the wreck of the Giannis D. A "deep dive" is generally defined for the purposes of this PADI certification as in the range 18-30m. Our maximum depth for this class was 22.4m. One of the major issues to deal with a depth is "nitrogen narcosis" or "the rapture of the depths" (which is not the same as the bends, or decompression sickness, a much more serious condition).
Each of the three participants (a fourth had to postpone due to recurring equalization problems with her ears) were given a simple problem to solve at depth, usually to indicate differences in ability under the influence of narcosis. Being given the very easy problem of "5 x 13", I wasn't sure how I could improve on my 1 second response time at the surface. Revenging himself, my trainer just gave me "square root of 134" back on the boat, but I couldn't be bother to spend more time refining my 2 second response of "11.5 and a bit". [FWIW I learnt very early the simple trick that (n.5)^2 = n * (n+1) + 0.25, so 11.5^2 = 11 * 12 + 0.25 = 132.25]
Later that morning, we had a non-class dive on one of the world's most famous wrecks, the Thistlegorm. In 1941, it was sunk in a most spectacular fashion when two German bombers dropped a pair of 1000lb bombs on it. The resulting explosion not only ejected two locomotives, but brought down both the bombers. Jacques Cousteau discovered the wreck in 1956.
As I approached towards a depth of 25m, I suddenly became very uncomfortable with being underwater; I just did not want to be there. I quickly realised that I had a case of narcosis exhibiting in the form of extreme anxiety. Rather than bolting for the surface (a risky manouevre) I knew I had to manage the symptoms. Unfortunately distracting oneself from irrational panic is not the easiest thing to do. I tried ascending a few metres in the hope that the narcosis would reverse itself. This didn't happen, and I couldn't distract myself by focussing on the wreck, marine life or my gauges. I communicated my distress to my buddy Ben, and he took me to the surface. It was only at our 3 minute safety stop at 5m depth that the effect began to noticeably wear off. By the time I was out of the water, it was only a memory. I was nonetheless shaken enough to want to skip further dives that day. As tiredness and dehydration can contribute to your narc symptoms, I hoped that addressing these issues might help stave it off.
One of my fellow divers was reading aloud from Great Underwater Adventure Stories (ed. Kendall McDonald, 1973 British Sub-Aqua Club). The following extract from Lt-Commander Todd's "How to escape from a submarine 600 feet down" was rendered in a very pukka English accent:
Another test is the safe training of foreigners, many of whom cannot understand a word of English. It can easily be shown that foreigners do not necessarily understand English better when it is shouted louder. And the addition of Savez? or Compris? after each sentence does not always help, even with Frenchmen, though it can be quite effective.