My rebreather try-dive
Hello, my name is Julia and….. I am a SCUBA junkie.
I’m pretty sure most people reading this can relate to my love of blowing bubbles, and this is why it’s probably been a hesitation of mine to try Closed Circuit Rebreather diving.
I’d heard the stories from my colleagues on how you can no longer rely on your breath for buoyancy control (that is second nature to me) and the difficulties swapping between open and closed circuit. Apparently, the experience is not dissimilar to being an intro diver again on a Discover Scuba dive. I felt my hand flailing days were over and if I’m honest I wasn’t sure my ego could take that kind of a knock.
However, it’s low season here in Cayman and we have an awesome boss who encourages us to learn new skills, so it was now or never to do a ‘try dive’, time to woMAN up and hit the water with my friend and fellow dive Instructor Serena Evans.
As I am a massive control freak I wanted to be involved in set-up of the unit, plus I was interested in learning about all the equipment and terms I had heard so much about, ‘scrubber’, ‘bail out tanks’, ‘counter lungs’ and ‘loops’, which is a whole new world for me.
Serena patiently took me through all parts of the unit. I was told to forget everything SCUBA had taught me in terms of buoyancy, this time I would be relying on this expensive equipment for my position in the water. Luckily, Divetech has rental units so you can try before you buy. I listened carefully to the do’s and don’ts, conscious that the rebreather on my back was more expensive than my car* and to take good care of it.
Under the guidance of my Instructor I wasn’t required to do much more than breathe and not scrape along the bottom of the sea bed. However, maintaining buoyancy was now controlled by gas in the unit and loop (breathing device), I had to exhale through loosened lips or out through the nose to descend. I had to add gas (either 02 or diluent) to ascend, all of which needs to be done whilst maintaining a partial pressure of 1.2 on the large computer strapped to my wrist. Sounds simple, sure!
At the time of jump I had butterflies, I haven’t felt that way for years and it was quite humbling to go back to the stage I often take my students through. Once in the water I felt pretty comfortable, this was my second home, having done hundreds of dives at Lighthouse Point this is more familiar to me than my couch. Decent was good, I didn’t hit the bottom, HA, I thought this is easy. I am a rebreather natural, maybe even a genius…. untill I did the first skill.
To start I practiced manually adding 02 & ‘Diluent’ in to the system which promptly flipped me on my head and flooded my mask. On a closed loop with no exhaust, this gas has no means of escape trapped in the wing, it sent me upward.
I then cleared my mask and as a result hit the bottom, escaping bubbles will send you downward, so now neither my knees or ego was protected anymore.
This process took a while, maybe 20 minutes of practicing the skill of manually adding gas in to the system, monitoring your PO2 (needs to be 1.2) and safety procedures, such as how to ‘Bail out’, which is switching to Open Circuit at the flip of a switch on the loop (my safety net).
Once my instructor was confident I had grasped the basics we swam out to the mini wall and descended to 40ft, this is when I started to get a glimpse of what all the excitement is about.
The first thing I noticed was the peace and calm, as the system is ‘closed’ you don’t have the noise of the bubbles escaping, so no ‘Darth Vader’ impressions. Now, all of a sudden it was me, at one, with the ocean sounds.
One of the most remarkable things you’ll notice is that the fish stop avoiding you, in fact a few almost bumped into me, it was as if they didn’t notice I was there, it was remarkable. If you want to feel ‘at one’ with the marine life this is as close as you are going to get.
But for me, the most unexpected part was physical feeling, it’s hard to describe but it felt as though I was gliding through silk, with no bubbles to interfere with ripples in the water I felt the serenity of the sea.
There’re many benefits to rebreather diving; going deeper, the opportunity to explore new depths for longer, extended air consumption, safer dive profiles etc. but for me the escapism and silence that close circuit offers is the key to a new world and uninterrupted diving.
This sport / activity is for the cream of the crop in diving, a high-level training and understanding of the specialized equipment is essential. There are enviably more risks associated with the different mixes of gases, decompression limits and depths, but the exploration and working with the cutting edge of technology is what excites these divers, the community is growing in numbers and with popular events (including Divetech’s Innerspace) you can see how the comradery and experiences are an inevitable draw, now I can see how this is addictive. ….I wonder, do I really NEED a car?
*Dramatic effect, I have a 22-year-old rusty Rav 4