50m Dry Dive Experience
Greg Parker Dec 01, 2020
On a cold January evening in 2014, members of the Hidden Depths Dive Club set off for an evening of fun, laughter, learning and a little more laughter at the Midlands Hyperbaric Chamber in Rugby. The activity was a 50m ‘Dry Dive’ and was a sell out and huge success, so we just had to return again this year for more of the same. With plenty of new faces in the group for 2015, some of whom hadn’t even taken their first breaths underwater when we last visited the chamber, and some divers like myself returning for another go, we had a great mix of experience and enthusiasm.
Thankfully the journey from Bristol to Rugby was uninterrupted and we arrived a good 45 minutes before we were due. We parked up, walked into the chamber building and met Robbie, the Hyperbaric Supervisor & Technician, tucking into his dinner. Not put off by our early arrival we were shown the paperwork we needed to complete and were given drinks along with plenty of Quality Street chocolates to keep us entertained. Once everyone had arrived we were shown where to change into the stunning blue theatre scrubs you see in all the pictures!
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Robbie delivered the dive briefing, talking us through the main differences between dry and wet diving – mainly that we might find equalisation a little trickier and that we wouldn’t be getting wet on today’s dive, unless anyone presses the big red button that we were specifically told not to touch… I for one didn’t fancy getting drenched by the fire extinguishing system so kept well away from it!
The dive we were about to undertake would be following a US Navy schedule; (170FSW) 52.1m for 25min, although our bottom time was only going to be in the 12-14 minute range, with the extra decompression for added conservatism. Below are the times of our dive, along with my recollections.
19:43 Left the surface. Equalising like crazy within the first 20cm.
19:44 Arrived at 3m first stop. Everyone’s ears are equalising without issue so it’s on with the dive.
19:44 Left 3m. The descent to 50m is underway. Our chamber technician Spike constantly monitors us for any signs of discomfort, but nothing so far.
19:49 Arrived 50m. Everyone arrives safely with no equalisation issues, and the temperature in the chamber has dramatically increased.
A song erupts and the many balloons, neoprene squares and children’s play balls that are here to highlight Boyle’s law, are soon being thrown around the chamber. With the increase in air density in the chamber this isn’t as easy as you might imagine, and leaves most people in fits of giggles. Others are laughing at our distorted voices or posing for pictures from the outside world. We are then given a seemingly simple task using magnetic letters and a laminated card with numbers on it. Our slowed reactions and coordination highlight the effects that gas narcosis has on us at this depth, and trying to concentrate long enough on the task is hard.
19:57 Left 50m. Our 8 minute bottom time is over, so it’s on with the ear defenders and our ascent begins.
20:01 Arrived 12m, 1 minute deco breathing air. The warm air from the chamber has rapidly become cold and moist during the ascent, leaving a fog in the air.
20:02 Left 12m.
20:03 Arrived 9m for our second deco stop, and the first on Oxygen.
20:03 Masks on, breathing 100% 02 @1.9 pp02. Spike helps us adjust the oxygen masks to fit, and we can sit back and relax whilst decompressing.
20:07 Depart 9m
20:08 Arrive at 6m @1.6 pp02. Our final decompression stop at 6m lasts for 22 minutes, but it flies by. With Spike’s fascinating recollections of his days in the Navy, submarine escape studies and tales of goats in dive chambers we have soon completed our time at 6m.
20:30 Depart 6m. Our deco is complete, and it’s time to head back to surface pressure.
20:31 Off 02, and resume breathing the air in the chamber.
20:32 Arrive safely back at the surface.
With the dive over all that was left was to get changed back to the normal clothes we arrived in, collect our goodie bags with free T-Shirts, water bottles and magazines, and say our thanks and goodbyes. Everyone was buzzing with their recollections of the dive and so we set off for Titash, a local Indian restaurant, for a curry and to talk over the experience once again.
My thanks go out to the Midlands Hyperbaric Chamber and in particular Robbie for his excellent briefing and chamber operation, Spike for his help on the dive, and to Andy for the dive photos and all round assistance. A fantastic evening, and I’m sure we will be returning again next year!
Written by Greg Parker, PADI Master Instructor
First Published March 2015
