Hey there,
it is me
again. Long time no see? Well, we have had a couple of busy days… Yara and I
are still doing our nudi-research-stuff (as some might call it)… But in the
technical facility a lot is happening! And I am very glad that I am getting the
chance to learn a little bit more about diving and especially see what
technical diving looks like.
Jon is
doing a course on CCR Mod 2 (closed-circuit-rebreather normoxic trimix) for
Luca, a very nice Italian underwater photographer/economist living in Zimbabwe.
Deon (from Doxa beach hotel) is going along doing normoxic Trimix course on a
twin set. Sounds weird nonsense that nobody understands? Well, let me tell you
about it a little bit. After observing them for a few days and going diving
along I must say that it is basically a lot of theory learning and dive
planning and equipment set up and it looks kinda difficult…but still I got very
jealous and I think it is worth it!
Yesterday
we went to a really nice rock coral reef here called Yogis. 30 m depth for
Yara and me, around 45 m for them. 40 min dive for us, 70 min for them… Starting
to understand why I got jealous? I was doing a nudi search per time survey and
I couldn’t help but to fall in love with the reef. We had such a good
visibility and the light coming through till 30 m made the fish and corals
very colorful. I even found some nudis just when I was about to hit my deco-time!
The nembrotha purpureolineata (on the picture) was really beautiful; I had
never seen it before and I felt lucky to spot it in the end!
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| Nembrotha purpureolineata. Don't her "devil-like red" rhinophores look extremely cool!? |
Nonetheless,
yesterday was really the first time where I actually felt sad and like a kid
after a dive even though I consider I have a good diving knowledge and
experience. It’s that feeling you have as a kid when you are not allowed to go
along to fun places with the adults just because you are little and have not
enough experience or knowledge. Or when they send you to bed to sleep and they
can still stay up. From the first second I was happy to be at Yogis. And I was
looking and looking for nudibranchs and identifying the fish and being glad of
being there. But my time was running out! And that´s when it struck me: I wanted
to get more bottom time there because I liked it too much but I lack the
technical diving experience and the decompression theory that the boys have and
are learning and discussing every day and which allowed them to stay longer and
deeper.
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| Deon (left), Jon (middle) and Luca (right) planning their dive. |
According
to NOAA, “technical diving is a term used to describe all diving methods that
exceed the limits imposed on depth and/or immersion time for recreational scuba
diving. Technical diving often involves the use of special gas mixtures (rather
than compressed air) for breathing.”
I will not
bore you with all the theoretical details. I don’t think I could make justice
of it anyway. Although it doesn’t seem to be “rocket science” it takes a lot of
learning and reading in order to properly understand about what you have to do,
setting up your equipment correctly and planning your dive in order to not get bent
or get other physiological problems.
Just
shortly, I dive with traditional recreational diving gear. The gas I breathe
from my tank is compressed air (which is basically made out of oxygen and
nitrogen) and I exhale the part I do not need as bubbles. You cannot stay
forever under water breathing that air, because you use it up. There are gas mixes
that allow you to stay longer because they have higher oxygen content, but to
not get oxygen toxicity (oxygen gets toxic under a certain pressure) you have
to watch your depth and are not allowed to go under a certain depth.
Basically,
with compressed air you are allowed to go deep but not stay long, with the gas
mixes (in this case I am referring to Nitrox) with higher oxygen content you
are allowed to stay longer but not as deep. You get into a shameful dilemma
when you want to enjoy a deep reef or wreck but not only for 2 min.
Okay, now
to the rebreather. A rebreather (in this case a closed circuit, which Luca and
Jon are using) uses the gas you are exhaling and kinda filters it. The carbon
dioxide you are breathing out (and for example on land is being used by trees to
make oxygen) gets bound and removed from the system and the other gases are
being reused. The system basically works in a way, that it gives you the best gas
mix for each depth you are at. In order for you to not get oxygen toxicity you
have to set up the system correctly and for that you need to understand the
background behind the system…Moreover, it uses smaller tanks, because it is
reusing part of the gas that is being exhaled!
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| The guys doing a deco stop at around 4.5m…notice the bubble free Luca (middle) and Jon (left) and the bubbles coming out of Deon (right)? They were very serious and checking their computers, which is very important, because they tell you about your gas mix, time, depth, etc. |
So now we have three guys, using two stage bottles each, and tanks with gas mixes. For all three of them, the gas mixes have to be pumped separately in advance and checked individually by each diver prior to the dive. A dive plan with air comsumption, depth and time at every depth has to be done and discussed and every single gas is being taken into account. Basically this means, they are working the whole day, either pumping gases into tanks (Jon does this very loudly in the centre…still…it is a “necessary noise”), discussing the theory and planning their dive or setting up their equipment. Notice the number of stage bottles on the after the dive!
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| Equipment of three technical divers: two rebreathers on the counter, one twin set standing up on the floor and the stage bottles laying on the floor…Jon smiling…everything went according to plan! |
Today, we
girls stayed on land doing lab work and data entry, the boys went to the
Klipfontein, which is a wreck at around 55 m bottom depth. Yara is going along tomorrow
and I will have my day off…understand what I mean by “feeling like a kid that
cannot go with the adults”??...thinking about doing technical diving now…but don’t
tell my mum! ;)
There is a
joke going around the internet: “With all these rebreathers onboard there
will be lots of space on the trip back!”… At least with Jon, you can see it stays a joke! They all came back
and had a great time on the Klipfontein. And they are preparing their next dive
very seriously already!
I’ll keep you posted about my work here, until then…baba :D
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| A redfang triggerfish (middle of the pic in blue) sleeping during the day at Yogis. |
