Dive Profiles from WC

[jome]

All in all it would be interesting to know how severe narcosis is at those depths. Certainly there must be some noticable effect? But no one is really talking about it...

At 100+ with lungs packed absolutely full, I would imagine one is pretty out of it...

 

[AltSaint]

Simo

Only Natalia can answer that one. In fact we did have to let the organisers know how long our dive times were. I think they allowed up to 30 seconds over the estimate before deploying the counterweight. Unfortunately though, we weren't briefed on this ( or if we were, I missed that ). My dive times can vary, so I estimated in the middle. When I found out about the 30 second delay, I advised the judges to add another 15 seconds to my estimate, in case I had a slow ascent.

 

[Jorg]

Actualy it was only 10 seconds. So to take an example: Peter Pedersen announced 85 meters in 2:20, so at 2:30 the counterbalance system would have been activated. During the eventcommittee it was mentioned, that's why some people gave on purpose longer divetimes then what they actually should do, just to be sure. That's what we found out afterwards... Of course this is not smart!!!

We, the judges, tested the counterbalance system very good, and I must say I was pretty happy, even impressed, with the speed it reached to get everything up.

Soon some more pictures and video's on www.shark.nu

 

[AltSaint]

There are advantages and disadvantages to letting the athletes know about the deployment delay. As you suggested Jorg, some will put in contingency that then compromises safety. For most though, I think it would make them think more about putting something more accurate down. I was justified in adding 15 seconds, as my dive time then came within 2 seconds of the revised estimate.

 

[Jorg]

Just for some extra info, as I was an in-the-water-judge here... During Natalia's dive at around 1:45-2:00 min the safety freedivers went down together with judge Bill. Fred Buyle was also in the water and dived around 30 seconds later. I could just see the safety divers at around 25 meters waiting for any sign of Natalia, at one point safety divers came up together with gesturing that she wasn't there, so I told to the safety guy on the boat to activate the counterbalance. Fred was still waiting there, and 10 seconds after the counterbalance was activated, Fred signed to me he did see here coming, I told the safety and they stopped the counterbalance. Natalia really took here time! She came up and looked pretty okay (after doing a 86 meter dive!), and because of the little chaos on top didn't know exactly where to look at. She came up with a bloodnose (I have seen maaaaannnnyyy bloodnoses during this competition!). All in all a slight nerve wrecking experience, but very interesting to see that procedures worked just fine.

 

[jome]

Just out of curioisity...Approximately how long would the counter balance have had to been dropping to reach her and start pulling her up? (and thus, I guess, leading to DQ?)

In other words, how fast does it drop

Maybe she had a reverse block in the forehead and was taking her time because of that (bloody nose) If anyone knows her email, please pm me...I'd really like to ask (and I have a bunch of other questions as well).

 

[Jorg]

If I remember correctly about the test we did it was something around 3m/s. And the guys still controlled it by applying the brake, so it could have gone even faster!

 

[ivan-il]

freediving2004@list.ru

 

[Haydn]

It must be a real worry for safety divers and officials to realise a diver is still out of sight beyond 'normal' time limits for that dive. More so if the safety freediver is hanging around at 25m, running out of air, and needs to return to the surface. The solution is simple. Just place a scuba diver two thirds down the line with radio contact to the surface. He can report diver in site, diver at bottom, diver turning etc, when diver passes him, the safety freedivers commence their dives. No need to do this for depths shallower than 50 metres. I just shudder thinking about Mark P in Cyprus being brought back by Francois and Loic, deep water rescues only happen rarely, but every one is on the edge of a fatality.

 

[Jorg]

What exactly happened to Mark P????

 

[samdive]

Mark in Cyprus - I think he burst an ear drum or something on the way down, lost his sense of direction and did his whole dive in a corkscrew. Then he blacked out around 12m on coming up and the safety divers were not quite in the right place as his dive took too long and they had had to come back up for air. He was also a huge guy and it took two of them to lift him up. Once up he was pretty blue and had to be got out onto the pontoon and on O2 before he came around - it was his first comp. He hasn't been seen since!

Haydn - correct me if I am wrong - he is your brother in law isn't he?

 

[Jee]

The thing with Natalia's and Mandy's graph is that the D9 was on 20 sec sample mode. (on the computer Mandy did 81.1 and Natalia 88.2... and Herbert 106.9, Carlos 104.2, Nery 102.7)

regards,
Bill

Why not set to 1 second sample? I think there would have been enough memory for a more detailed profile, (and more accurate max depth measure) in the D9s, am I right?

 

[samdive]

We did set them to 1second as soon as we realised they were not already set to it

 

[fpernett]

I came a little late to this thread. (someone in my house have to work).
The Natalia's profile is very similar to my profiles when I'm with a huge ballast.
She seems to start sinking at around 18 meters. But if we are going to copy the really deep diving mammals, then sinking is the way to go. The picture attached is from a study published in 2000 in Science Magazine. The Weddell seal start sinking at around 100 meters, for a dive to 400 meters. In fact, in a dive to 540 meters the gliding phase was 6.2 minutes. The average speed descent for the four species was 1.1 +/- 0.1 m/seg and the ascent speed was 1.0 +/- 0.2 m/seg but while continuous stroking, at around 100 meters in the ascent they switched to a stroke and glide strategy, and in the final 10 meters they glide to the surface without any stroking movement.

I think this article is very informative because I don't think we should think in terms of time limited dives. The speed of descent and ascent has to be matched to Oxygen Stores Consumption. Gliding the most in the descent phase will save a lot of oxygen stores, but with heavy ballast the ascent will burn the stores (that is not a problem in shallow dives, because anaerobic metabolism can provide that energy) but as we see in seal, a dive to 400 meters require at least 400 seconds of ascent, so they have to rely on Oxygen stores from the muscle.
The best way to match this diving mammals (in my opinion) is avoiding severe changes in buoyancy, no suit or very thin suit will be the best.

 

[Billextreme]

I add one more graph on the site... it's from Herbert own STINGER... (108,2m)

/Bill

ps. if there are more divers with interesting dive-graph's, mail them to me... an I put them on the site ...directly.

 

[OceanMan]

There's something about the graphs I don't actually understand...
A few dive profiles show a slow down in the descent (near 40m) which means the freediver starts to sink -> Ok. See Coste, Nery
But many dive profils don't show this slow down ! On the contrary the descent speed seems to increase. See Pedersen, Jattu, Kinnunen.

Why?

And Martin's dive descent speed is very linear.

 

[jome]

Difference in wetsuit and weight configuration coupled with a different straregy?

Some people like to start the sink quite early. It would make sense that they are thus carrying more weight. As they go deeper and deeper, the wet suit and lungs lose buoyancy and the decent accelerates. For others, maybe they kick down to -40 and don't carry any weights?

If I remember correctly, when I was in Nice Nery was training in a 7mm suit without any weights or something like that. I don't know if that was just training or if he competes like that too...Anyway, with that configuration, you might expect something like that.

 

[acho]

But if we are going to copy the really deep diving mammals...

Then we should do EXHALE dives, Seb's-style.

 

[AltSaint]

It would be interesting to see Sam Still's profile, as he was the only competitor without a suit on.

 

[Billextreme]

Sam Still's profile is now online... as well.

/B