On a recent trip to Truk Lagoon, I had my first and hopefully only experience of DCS. Fortunately, it was not severe and I did not need to go into a decompression chamber. I believe it was a diver error, most likely because I did not read my computer right. . . It was a deep dive just beyond the 50m mark and since we were all diving on single tank 24% nitrox, the dive plan was very carefully discussed. . . . Bottom time was strictly limited to 15 minutes . . . My own maximum depth was 51.4 metres and at exactly 15 minutes I began a slow ascent. . . . I checked my Aladin Tec 2G computer and thought it indicated a safety stop of 14 minutes. . . . Later check by the DM revealed that it should have been 22 minutes.
Feeling fine, I stripped off, had a cold shower and wrote-up the log. I then went to the lounge and was sipping a lemonade when I felt pain in my lower ribs. It quickly spread to the entire rib cage, both arms and shoulders and I felt weak and dizzy. I alerted a nearby divemaster who immediately made me lie down and administered 100% oxygen. After about an hour of that the pain gradually went away but the dizziness persisted for 4 to 5 hours. But the worst part of the ordeal was unbelivable weakness that lasted for almost 24 hours. . .
Thanks for a very interesting post and honest self-assessment! From my perspective, your presumptive self-diagnosis appears reasonable (or else, that was some really bad lemonade).
I have not yet been to Truk, so I am not familiar with the 'usual and customary' diving practices there. As a consequence, others (including the OP) should feel free to dismiss my comments, as being naive in the context of that environment. But, your post prompts some questions.
I would agree with some other responses, that this should be / have been considered a technical, decompression dive, and planned that way. Or, to put it another way, I would always plan a dive to 52 m for 15 minutes as a deco dive. That way, I would know, in advance, what to expect in terms of what stops, at what depths, for how long. That would possibly also reduce the likelihood of a misread of the computer. But, I get the impression that such was not the case, although perhaps the 'discussion' you mentioned was just that - planning for a deco dive. That is not a criticism, just a statement of my personal views. It may well be that doing a 52 m dive this way is the standard for Truk. Now, having said this, I readily admit that I have done a 'spontaneous' deco dive on two occasions - to recover objects after a dive - but did so after quick planning on shore, and taking decompression gases with me.
Did other divers follow approximately the same schedule that you did, or did the others in your group of 8 stay down longer on the ascent (e.g. were their stops more consistent with the '22 minutes' or the ~14 minutes)?
You mention diving a single cylinder, and I would be interested in knowing what size cylinder did you take on a 52 m / 15 min bottom time dive? Also, were you (more importantly, were the DMs) carrying a redundant air supply, at depth? You mentioned a cylinder hanging at a shallow depth, so I am curious what provisions are usually made on Truk, for dives like this.
Finally, is there a chamber on Truk? If not, then the failure of the boat op to transfer you to a medical facility with a chamber makes a lot of sense.
But, at least in the US, if the events occurred as described, I cannot think of a captain who would not insist that you be evaluated by competent medical personnel (yourself excluded, of course). Your presentation, in the context of the dive, and the administration of oxygen was - if I may use the term - and absolute indication for further evaluation.
I do not say this as a criticism of your actions - it could be that this reflects standard practice on Truk. I am curious, however.
