Sunday 29th June 2014
Why CCR (Closed Circuit Rebreather)?
For the most part I seem to have mastered sneaking up to most animals, but there are always animals that are skittish like Groupers, Eagle Rays, and Sharks.
A few weekends ago Ruth and Lee from BSAC on their rebreathers got two metres away from a Bull Shark and got amazing footage of it on their compact camera and Go Pro. I saw a Bull shark too on Open Circuit a week later, and despite creeping up on it could only get ten metres from it. The moral of the story is that it doesn’t matter how shit hot your camera is, if you can’t get close to the subject you can’t get the shot. Even with Mangrove video lights that each put out forty three hundred lumens, the light only travels so far.
So I booked in with Daren M. from Blue Label Diving and Dive Dive Dive and opted to learn on the Pathfinder simply because it’s a great travel rebreather being small and lightweight, and also because I can easily cross over thereafter to any other rebreather if I choose.
For those of you that don’t know what a rebreather is, it’s basically a system that allows you to dive longer because it allows you to have the best gas mix for your depth at all times. In short without confusing you, it also allows the diver to dive without blowing bubbles out because the diver’s breath is recycled into the rebreather loop. This means you can get super close to animal life because they don’t get scared off by the bubbles you would normally be breathing out if you were diving off open circuit your standard looking Scuba diver and it also mean you can stay down forever, well maybe not but a lot longer time than someone on Open Circuit.
Yesterday we started with theory in the classroom and building the rebreather which I found really interesting. Whilst I actually cottoned on fairly well to the physics behind it and found it all pretty common sense stuff, there sure was a lot to remember.
When I put the Pathfinder on initially I was blown away at how light it was. I felt like I had a basketball on my back. Bearing in mind I’ve dived Twins for a year and Sidemount for two years, the Pathfinder was lighter than both of those.
It also fit really well, and despite my previous thoughts that rebreather divers have hoses all over the place, all the hoses were routed to be neatly tucked away and everything was incredibly easy to access and manage.
So today we went down to the pool also with Nick K who was learning on the Poseidon Discovery Mark 6 rebreather; a fully automated rebreather which does all the thinking for you. So Nick pretty much got to swim around all day doing SFA! Laughs.
The Pathfinder is automated however does have manual override so I needed to learn how to operate it manually as well. There are obviously upsides for both types of systems.
We spent four hours in the pool and did various skills. I was surprised at how quickly I started to learn where everything was on the kit by touch. The biggest challenge for me was buoyancy control, because unlike Open Circuit when diving CCR you cannot use your lungs to cater for buoyancy.
This means you have to use your BCD or drysuit if applicable, and/or the counterlungs that infate and deflate when you breathe and are positioned on the rebreather. I found this quite bizarre, kind of like learning to dive all over again, but can see with practise that I will be able to do it just fine.
Every time you go up or down you must compensate your buoyancy, also matched with your rebreather adding in oxygen into the loop and counterlungs you also have to counteract this buoyancy change.
I found swimming around in the pool similar to having Twins on my back as far as turning and position went. Trim seemed fairly easy and I didn’t notice having a bail out bottle on my side at all.
Saturday 2nd and Sunday 3rd August 2014
This weekend we headed to my least favorite dive site the Tweed river in order to practice on the rebreather for my course. On Saturday we mostly dived around getting used to buoyancy changes and it was fairly nice visibility.
Rebreather divers talk about this ‘silence’ and it’s strange and somewhat unnerving. It’s like fully immersing your head in the bath and you hear this intense silence and your heart beating so loud it sounds like it’s going to pop right out of your chest. Then an Eagle ray swims by, a baby one, usually on open circuit it would’ve been startled and darted away but this one looked at me and came right over to say hi. It was cool. All of a sudden I saw the beauty that is the ‘silence’ of diving Rebreathers.
Flying the rebreather manually does seem somewhat labour intensive and I can see why photographers would probably not want to go solely for a manual rebreather as you have to pay attention to what is going on a lot of the time.
I’m feeling good after a big weekend diving and one hundred and eighty minutes clocked up and looking forward to diving the Brisbane ex HMAS. So far so good and talking about me crossing over to the Poseidon Mark 6 or 7 instead due to it being fully automated.
Saturday 4th and Sunday 5th October
So due to weather, my trip to Tonga and then being sick I haven’t posted an update nor finished my CCR course for a while. In the interim I decided instead of the ICS Pathfinder to convert to learning on the Poseidon Mark 6.
As a Videographer who wants to concentrate on filming rather than my unit I thought for me the 7 would be better because it is fully automated and does everything for you. Therefore making all the drills and skills you learn on the Pathfinder redundant. If anything is wrong it vibrates and you bail out and call the dive. My kind of unit!
I can still get the technical counter lungs and battery for the deeper diving too and still manually add Oxygen so I’m pretty happy with my decision. For my diving it suits me.
So after a mandatory pool session we headed out on Sunreef to dive the Brisbane Ex HMAS wreck Saturday and Sunday to finish the course.
It took about an hour in the classroom to put the unit together slowly from scratch and chatting to my instructor. I could see this was pretty simple, unlike the Pathfinder you don’t pack any sorb in the canister it is pre-packed so you literally check the date on it and chuck it in place, which I love the most about it because I hate packing the sorb. I have small girly weak hands and struggle to push the lid down. You can get pre-packed sorb for the Pathfinder but I believe this might be quite costly if doing it on a regular basis.
Turn the handset on and it runs through all the tests for you, all you need to do is take a few breaths out of it and then later on before the dive pre-breathe out of it for three hundred seconds.
So on the boat whilst you are getting out to site this can be done and then gearing up is basic you just clip on the wing, masks and fins and Sidemount the bail out bottle which takes all of about twenty seconds. It’s so quick and easy I think it’s faster than diving Sidemount actually.
I was pleasantly surprised after being on boats looking at CCR divers thinking man that looks like such a hassle. I suppose it depends on their unit and how comfortable they are with it. But to put all myths at bay gearing up in a rebreather is actually simple.
Bouyancy is obviously the big learning curve with CCR. Like anything practise makes perfect and I already noticed a huge improvement over the weekend in my use of Diluent and my comfort in the water. Once you find that G spot with your buoyancy it feels really good.
It didn’t take me long at all to see the huge benefits to diving CCR, a Grey Nurse shark approached our group and gobbled a big Kingfish whole right in front of us! It was awesome! Then we were welcomed into schools of various fish like Jewfish and Snapper and hovered ten centimetres away from Flathead who were stacked on top of one another.
The marine life treat you differently when you’re on CCR. Firstly they notice you, but are not phased by you, then they just accept you as if you were a large animal that they wanted to follow around.
I can see why CCR divers are a bit more hands on, for example they may grab the wreck and pull themselves up a metre instead of inflating their wing and using up their Diluent. This does seem like a faster more efficient thing to do especially when your profile is up and down over obstacles. Unlike open circuit, in CCR you can’t use your lungs to lift you up or down in the water.
On Sunday I did my first blue water ascents which I was a little anxious about after hearing how it can be quite hard in a drysuit. Namely as you have three different airspaces to control on the way up; your counterlungs, your drysuit and your wing. I seemed to manage it okay probably cautiously staying a little deeper at seven metres until I felt comfortable.
The last dive of the day we did a blue water ascent and smb deployment at the safety stop. I actually felt pretty good about how I went with that considering I don’t often deploy an smb when diving Open Circuit, when I have my camera and usually allow the boys to do it instead.
The bail out is easy to un-clip in the water and pass up, then jump on the boat with the rebreather on my back.
So now I am a certified CCR Air Diluent Poseidon Mark 6/7 diver.
*Disclaimer: This is only an article about my experience of learning CCR and should not be taken as advice. If you want advice on rebreathers I recommend only getting advice from the best CCR instructors possible, who have years of experience diving CCR on various systems available.