The club did one several years back (before I joined) and one of the guys who did the dry dive returned later in the day as a precaution because he was concerned he might be exhibiting some signs of DCI. We can not be sure if it was DCI and the guy from what I hear had been busy the day before doing some hard labour so it may have muscle fatigue simple due to that or at the other end of the scale a contributing factor to a real case of DCI, we just don't know. I have never had a chance to meet the guy, so I only know what I have been told by a third person who was present at the time.
This has been up for debate in our club recently because us younguns are interested in doing it. The third person who told the story would do it again but was keen to emphasis the risks involved. I would have assumed that the risks for DCI are lower on a pot dive even to 50m compared to a 30m wet dive because ascent is controlled (presumably well within the tables), you are more comfortable, warm and not in the dark.
Also some of our members went on a technical visit to the National Hyperbaric Chamber in Aberdeen a few weeks ago. One of them then emailed NHC asking if they organise dry dives with an interest in experiencing and learning about the effects of being narked. We got the following response;
'I'm glad you enjoyed the visit and it gave you something to think about.
Please advise your diving club that we do not want to see them, ever, unless it is under planned visit circumstances...
As to the dry-dive, it is not something that we offer and unfortunately need to decline your request. It involves an element of risk which we are keen to avoid and the best advice to your club is to recognise that narcosis will happen and to plan accordingly, or ideally avoid it.
If you wish to have a visit at some point to see the NHC than we could arrange depending upon dates, activities here and numbers.'
That's fair enough, I really hope I'll never ended up in Aberdeen unless it is under planned circumstances
Joking aside it gives no info on the element of risk and it is this I am keen to learn more about. Can any one point me in the direction of incident reports or data on the number of incidents of DCI due to chamber dives?