Jan 062015

Petrel at 60m

I have just returned from ten days in Bali, and nearly 20 hours of time underwater. After doing the MOD1 course on my rEvo in warm Indonesian waters back in 2013, it seemed like time to repeat the experience with a little more depth. I’ve done enough rEvo diving over the intervening period that I was comfortable with the combined MOD2 and MOD3 courses in one trip. The plan was for skills, drills, theory, work up dives and an eventual dive to 100m. First up was the MOD2 for normoxic trimix bailout.

Marc Crane on rEvo

Of course, as per the MOD1 course the camera came along for the ride. I installed the deep spring kit in my Aquatica housing prior to the trip to allow for dives past the 60m the regular springs are rated for. And by carrying the camera through all the simulated failures, I picked up a few new interesting tricks which I’ll cover in a later post.

Marc runs a practically-oriented course and we were in the water the first afternoon after a morning of theory. My first dive wasn’t particularly comfortable with three ally 80cuf tanks hanging around at all angles. By the end of the dive I’d determined that some of the tank rigging needed to move and also remembered that my rEvo harness was still sized for drysuit.

With some movement of straps, clips and bungee lines the subsequent dives were more streamlined. Even with everything attached to my liking there’s an awful lot of space taken up by all that gear. My movement through the water was somewhat slower than usual as the bailout tanks plus camera created their own momentum. Stopping and turning became difficult and going backwards became impossible. Luckily there’s a bit more space in the ocean than your average cave.

Over the first four days in the water we covered the appropriate reactions to low PO2, uncertain cell readings, loss of primary controller, stage retrieval, out of gas swims and the mysterious cable tie on the oxygen MAV button, among others. Up top there were best gas mix calculations, deco planning, contingency discussions and an interesting chat about isobaric counter diffusion.

Along the way I learnt that keeping two helium mixes on the left hand side and a full deco mix on the right hand side meant I’d be floating at a dead goldfish angle for much of the dive. I also rediscovered how much I hate swimming around in the ocean without a mask on – that salty stuff is nasty on the eyes. But it did demonstrate that I can maintain effective PO2 control using the rEvo dream HUDs and a bit of a squint. And after some calculator machinations I determined I can probably use a deep bailout mix for a 60m dive that will also work as an intermediate bailout mix for a 100m dive.

The first photo up top is a selfie of my computer taken on the last dive of the MOD2 course. This was all about seeing if I could get my arm out at the right angle to see the numbers. The diver below is Marc, with his head down as he leafs through his wetnotes for the next failure scenario. The second shot is a close up of same, with the book momentarily closed as he tries to determine why I’m taking photo instead of paying attention. And the last photo here is a group shot showing the number of closed circuit divers hanging out at Villa Alba. It’s always nice to outnumber the bubblers!

Rebreathers at Villa Alba

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