As part of the wide-ranging dives
offered by Kingston and Elmbridge, the club arranged for several groups to take part in a 50m ‘dry’ dive at the London Diving Chamber in St. John’s Wood. After a frustrating day trying to explain the concept of a dry dive to confused colleagues (“So they lower the chamber 50m under water?”) we arrived at the site, which is part of the Hospital of St John and St. Elizabeth. The staff at the chamber were friendly and informative, and after a quick change into the regulation blue scrubs (flattering AND stylish!) we listened to the pre-dive safety briefing. In addition to the treatment of divers suffering from DCI, the chamber is also used to treat diabetic ulcers and different wounds. Then, it was into the ‘pot’.
The pot actually looks like a very small, cream submarine (at least to my somewhat uneducated eyes) in the middle of the room. Entry is through a round hatch into a transfer area, then through another hatch into the main chamber, where we made ourselves comfortable on the benches, put our computers in the bucket of water and began our descent.
The need to equalise is much more frequent than in water, and took most of our attention until we hit 50m. We then amused ourselves immensely squawking in Donald Duck voices at each other, insisting that we’d spotted a shark lurking in the depths and tucking into Mars bars that I think had been brought for some scientific reason that passed me by. We did a little written test in mental ability to compare with one taken at ‘surface’ level earlier, with the expected huge difference in mental agility. Don’t let any diver try and tell that they’ve never been narked and don’t get effected by depth.
The combined effects of pressure and general hilarity meant the chamber was quite hot and steamy by the time we began the ascent, not a situation I ever expected to be in with my fellow divers! The chamber uses US Navy tables but errs heavily in the side of caution, so the decompression schedule was 1 minute at 12m, 4 minutes at 9m and 23 minutes at 6m, all on 100% O2. And there ended our 50m dry dive, the staff gave more advice on what to do and what to avoid for the next 24 hours, and were happy to answer all our questions. For any divers who’ve never been in a decompression chamber, I’d highly recommend this experience, it was informative and enlightening and, most importantly, highlighted the need for extra caution during deep dives. And guaranteed no seasickness!
Report by Leanne Collinson