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Nemo 33 : The World's Deepest Pool

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Anonymous Squrrel
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Nemo 33 : The World's Deepest Pool

Tue Apr 23, 2013 7:17 pm
Here is a video from my trip at Nemo 33, the deepest indoor pool in the world:



Edited in Kdenlive on Ubuntu 12.10, and filmed with a GoPro HD Hero2 and its underwater housing, at 1080p in 25 fps.
lefthook
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Nice place. You should attach the camera to something heavy, perhaps water filled tank to stabilize it?...
DiveO
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@lefthook: I think Kevin did that on purpose; it's okay in this context. Of course, nothing for a slow pace underwater film, but that's not the intent here I would assume. It's more about the fun.

The only thing giving me the creeps is not the filming but the SCUBA girl ascending by swimming upwards. This is dangerous as she can easily gain too much ascent rate and she doesn't have proper buoyancy, otherwise she wouldn't use her fins. Safe ascending is in horizontal position, lying in the water and slowly ascending by using your lung volume and closely controlling your BCD's air volume at any time. You don't use fins for ascend, except in emergency.
DiveO
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I like the trailer where you are sitting upside down in the opening. Very nice idea.

Hero 2 ... oh well ... even under the good lighting conditions in Nemo 33 you can clearly see the white balancing being unbalanced. In shallow depths you have almost normal colors while with more depth everything is drowning in green, albeit not as bad as in free water conditions. Some color correction in post could correct this to make the different scenes match colors to some extend.

That's why I put my Hero 2 on the shelf and am using the Hero 3 Blackies, because they allow me to switch white balancing off "wb raw" in Protune modes. Color correction then becomes much easier in post, I can tell you.
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ttguy
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Hey Diveo just watched it again to see "SCUBA girl ascending by swimming upwards". But I can't see the dangerous bit. At what time code?

Very nice video by the way.
DiveO
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1:30 and following. Her ascending speed is much more than 10m per minute. Remember: 10m/min is one meter every six seconds. She seems to be around 1m/s, approx six times as fast. She is stressing her body extremely, especially if she has been at 10+ meters as there will be a lot of at least microbubbles forming that act as kernels for larger bubbles. If she goes up and down all the time, her blood will be full of bubbles.

She should ascend very slowly and not in upright position ... albeit this is what PADI and SSI are teaching against better medical knowledge.

The problem is that your body may very well tolerate your bad behavior for a long time. Then, some day, you are on a trip, hot temperature, sunny to the max, you didn't drink enough, some stress ... and bang! bends. Or you get a DCS an hour after your dive when you carry your heavy equipment to the shore. It always the same...

Saw that many times and many doctors told me also so. If just they would teach beginners correct diving there would be much less diving accidents.
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ttguy
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Man that was 2 secs of footage. You don't know that that was an accent. You can fin up for a few secs. It is all about the the total overall assent rate right?

Anyway. Very off topic for this forum. Whoops. Might have to ban my self.
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ttguy
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Man that was 2 secs of footage. You don't know that that was an accent. You can fin up for a few secs. It is all about the the total overall assent rate right?

Anyway. Very off topic for this forum. Whoops. Might have to ban my self.
DiveO
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Its not about overall ascent rate, but about the current rate at any moment of time, as this is about simple fluid and tissue physics and physics don't care about your two seconds. But please go for yourself, I know why I'm sticking with experienced and seasoned divers that survived several decades of diving without problems. And they taught me to be very careful about ascents because they have seen all that.
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ttguy
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At the risk of having to ban my self for off topic chatter
http://www.diverssupport.com/ascending.htm

So now that we know what the ascent should be, how can we actually perform these slower ascents. Ascent rates can be viewed as "mini decompression stops" and can be performed in stages. There are two ways to perform this ascent rate in a very easy manner. The first is to come up 10 feet and wait until the time catches up. In other words, for an ascent rate of 30 feet per minute, it should take 20 seconds to come up 10 feet. For example, if it takes the diver 5 seconds to come up 10 feet, the diver then waits another 15 seconds before going up another 10 feet. The ascent rate between the different 10 foot "mini stops" isn't overly critical as long as one does not ascend more than 10 feet at one time and does not "rocket" to the stop.


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