While I was in Grand Cayman on vacation I took the chance to try out a closed circuit re-breather. This is different from normal open-circuit SCUBA gear in that you re-breath the same air.
I remember when these units first started to be available for recreational diving a good few years back, it always peaked my interest, so I couldn’t miss a chance to finally give one a go.
DiveTech run a re-breather experience course for an afternoon (highly recommend giving it a go if you get a chance), Steve Tippets ran the course, another Brit and really good instructor. To my surprise I didn’t get to try one in a pool, as I had expected, but I got to go on an actual shore dive with it. After spending a bit of time in the classroom on safety and dive theory we then got familiar with the re-breather. After some basic skill tests, to make sure I could operate everything with one hand, we got kitted up for the dive.
We walked down the pier and climbed into the water, swam out a little way and then descended. That’s where the difference between normal diving hits you, the buoyancy control is very different – breathing no longer changes your buoyancy the same way it does with normal open-circuit gear. It’s not untypical for first timers to bounce around on the bottom or keep hitting the surface as they try to get accustomed to the re-breather. Fortunately, I bounced once, settled down and then got the hang of it…which meant we could then spend the whole time actually diving. The biggest difference you notice is how quite it is, with no bubbles escaping you can literally swim into the middle of a shoal of fish and have them swimming around you, normally your breathing would have scared them off.
The buoyancy control is quite different to normal diving, normally breathing out causes you to sink as you lose buoyancy, and breathing in causes you to rise. Well, with a re-breather it’s the opposite, although to a lesser degree. After a while you get use to it, but every now and then it catches you out as you try to breath out to stop rising, to only then rise further.
All in all great fun and many thanks to Steve. I might be back one of these days to take the full course.
Rebreather Dive, a set on Flickr.
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