Wow, I used to think diving in a drysuit would take a LOT more lead, so I was surprised the diver here only needed 2kg lead blocks, as that's the same amount I need diving a single al80 in a 3mm wetsuit. I'm aware of the negative buoyancy characteristics of steel tanks, but the image of drysuit divers carrying plenty kilos of lead was somehow seared into my brain. On that note, I've never had to dive in a drysuit, but would definitely like to try it someday. Thanks for the demonstration!👌
This is why it is always best to be trained in any activity before trying it. We all have dangerous misconceptions & mental lapses that we might not until too late.
Great video and thanks for showing. A BCD failure is something I really want to do more training with (not doing as you did obviously!) as it's the little bugbear that is on my mind during a dive, rational or otherwise. I've only just finished OW training and about to do dry suit training. Once I have my own gear I'll feel a lot more comfortable with knowing my own correct weightings for different scenarios and always want to make sure I'm not overweighted. Having to switch borrowed gear makes it more difficult to track and be certain about with limited dive numbers and I hope that having a number of dives with mostly (+/- undersuit volume) my own gear will give a lot more confidence.
Awesome video guys! For the SMB, isn't it better to just shoot it up and use the line for buoyancy? This way you don't risk loosing it and also you don't need to dump any air out as you assend?
Cool concept but actually going into deco without your wing was pretty silly. You could have done an ndl dive for this experiment... if you had a neck seal failure you would have had an unnecessary problem?
4 tanks of more or less 11 - 12 L filled at 200bar it's nearly 11kg of air... I find it to be very strange to be able to compensate with your lungs. You're saying he is correctly weighted, but It really makes me wonder if he would have enough weight to stay stable at 3m with nearly empty tanks. Could you explain how can anyone compensate 11kg of air with a lung volumen which is rarely more than 6L (and that would be compared with a completelly empty pair of lungs).
Hi, So yes, you are adding up all the gas weights (2.7kg for 200b in an Alu S80, 2.9kg for 200b in a 12L). But we are not suggesting you can lift that volume of weight without some buoyancy. We are suggesting that the gas in the dry suit, plus kicking up, along with the lungs (and either SMB or backup bladder) is enough to establish buoyancy. We would be ending the dive at this point and not taking so much more gas out of the cylinders. We also need to consider that we won't weight ourselves for zero bar, but at something more realistic like 50b for the main tanks. If we used this much gas on the dive, then the deco obligation would not be so high as to need more than 50b from each deco cylinder (plus we would have had something interesting happen to make us go so much over plan). Additionally, at around 100b the Alu cylinders are neutral and for the maximum bottom time we would get when obeying a minimum gas rule, we would not take more than 50b out of each deco cylinder. If we were in a situation where these deco cylinders did become positive, then we also have the option to ditch those. I do accept that the total pressure you weight yourself for will change the weights you may want to carry, but at the same time you have to consider all the other aspects when you are making this type of technical dive and what is likely vs unlikely (e.g. to have more than 100b needed of deco gas you had to of overstayed your bottom time by a huge amount etc.). Lastly, we wanted to keep the idea on the suitability of the dry suit and other methods rather than go into all the considerations of the dive itself - because as you say, that is a bigger subject - and for sure if the wing failed, I would be heading up and not making these kinds of movies at the time :-) Hope that helps explain a bit more. Cheers.
@@wowfreaker Rubbish. They've said he's doing it on lung volume alone, with a slightly squeezed suit and empty wing bladder. He's barely negative like that.
BCD failure is rare they are all most foolproof, He could use his suit as a BCD ,the most gojng yo happen is he gets wet little cold ,but staying 15 minutes at 45 ft then ,decompressed
From what I can see, it really looks like he have a lot more air in his dry suit than is necessary to compensate for the squeeze... When diving technical you have 2 of everything that is important. This even mean double gear for buoyancy. So this isn't any more special than what's in the training for diving technical.
Yes, he puts more air into his drysuit that is needed that is kind of the whole point in the video, to show in a failure it could be done and still a safe ascent be made. If you watch again and listen to everything we say and example we show it should be clear. Cheers, Steve
Hi, I do not agree with the philosophy of this video because : - In case of a BCD failure, the buddy can help too - Having a buoyancy redundancy is compulsory for wetsuit (Tec)divers in areas with downward currents
Sorry, but there is NO WAY that he is correctly weighted. NO WAY. Air is 1.28g/L. EANX50 is ~1.34g/L So, an AL80 pumped to 200bar of air holds ~2.84kg of gas. He's got 4 of them strapped on, thereby got close to 11kg of gas mass (assuming there is no helium involved). In order to remain neutral throughout the dive he thereby NEEDS 11kg of lift that he can add at the start of the dive, and remove by the end of the dive after the gas in all cylinders has been breathed off. Looking at how he is with an empty wing and a squeezed suit, there is NO WAY that he is going to be able to stay underwater with 11kg of gas loss by the end of the dive. He's going to pop up like a cork, or wind up having to ditch empty tanks to shed buoyancy. Turns out a cave diver beat me to it, and has pointed this all out below...
Hi, Thanks for the comment and thinking about what we are showing. You are right about the mass of the gas of course. I am using 2 x 12L steel and a 2 x Alu80 BTW (not really related to the total mass) - but we are not weighting ourselves for zero bar, more like 50 bar, so the mass of gas is about 3/4 of the full 200bar fill. One thing that is often crossed is the idea of lift needed vs weight needed. They are not the same thing. If we need say 8kg of lift for the gas weight, that does not mean we need 8kg of lead. So we have lets say 8kg of lift needed at the start that we don't need at the end (200 bar to 50 bar usage in 4 tanks). We then just add whatever weight MIGHT be needed to keep us at 5m with those tanks at 50bar. This amount of weight is nothing to do with what we lost, only what we have at 50bar. And so if I have more muscle, I need less than if I am not as fit. If I am using thicker garments, I need more lead than if I had fewer garments. If I am in Salt, I need more lead than in Fresh. So the issue is not the weight we lose, but the weight we end up with. The lift of course depends on the gas weight we will lose - and so we are seeing if I can lift the 8kg using something other than the wing - and of course we already used a bit of gas getting to the wreck, so a little lighter by then too. Hope that explains a bit more? Cheers
"He could only do it because he was correctly weighted. Could you have done it if I added 4 kilos?"
"Certainly."
lol, called out instantly
Great video. The most common dive error I see as a recreational diver is over weighting. Keep spreading the message of proper weighting.
Thank you for filling in the gaps
just a beginner here, but this was very fascinating to watch!
Grea stuff. Very informative (and fun to watch too)
Amazing video, explanations and technique. Cheers
Great video I've struggled with air in a wing hard to dump , and pockets of air in the drysuit , fantastic information
Wow, I used to think diving in a drysuit would take a LOT more lead, so I was surprised the diver here only needed 2kg lead blocks, as that's the same amount I need diving a single al80 in a 3mm wetsuit. I'm aware of the negative buoyancy characteristics of steel tanks, but the image of drysuit divers carrying plenty kilos of lead was somehow seared into my brain. On that note, I've never had to dive in a drysuit, but would definitely like to try it someday. Thanks for the demonstration!👌
This is why it is always best to be trained in any activity before trying it. We all have dangerous misconceptions & mental lapses that we might not until too late.
Great video and thanks for showing. A BCD failure is something I really want to do more training with (not doing as you did obviously!) as it's the little bugbear that is on my mind during a dive, rational or otherwise. I've only just finished OW training and about to do dry suit training. Once I have my own gear I'll feel a lot more comfortable with knowing my own correct weightings for different scenarios and always want to make sure I'm not overweighted. Having to switch borrowed gear makes it more difficult to track and be certain about with limited dive numbers and I hope that having a number of dives with mostly (+/- undersuit volume) my own gear will give a lot more confidence.
He knows the bases of diving (theory and fisiology) very well, like everybody should knows.
4:14
"I tried it at home"
in my bath tub.
I died.
Great info. Would like to hear final thoughts on when a 2 redundancy bladder becomes a must, i am assuming it is depth related?
and what the problem if he HAS a dry suit?
i dont use wing, especially if correct weight, or even i have +1 or +2 kg in cold water...
thanks for this info..
Amazing experiment
Awesome video guys! For the SMB, isn't it better to just shoot it up and use the line for buoyancy? This way you don't risk loosing it and also you don't need to dump any air out as you assend?
nice
Good stuff
Cool concept but actually going into deco without your wing was pretty silly. You could have done an ndl dive for this experiment... if you had a neck seal failure you would have had an unnecessary problem?
4 tanks of more or less 11 - 12 L filled at 200bar it's nearly 11kg of air... I find it to be very strange to be able to compensate with your lungs.
You're saying he is correctly weighted, but It really makes me wonder if he would have enough weight to stay stable at 3m with nearly empty tanks.
Could you explain how can anyone compensate 11kg of air with a lung volumen which is rarely more than 6L (and that would be compared with a completelly empty pair of lungs).
Hi,
So yes, you are adding up all the gas weights (2.7kg for 200b in an Alu S80, 2.9kg for 200b in a 12L).
But we are not suggesting you can lift that volume of weight without some buoyancy. We are suggesting that the gas in the dry suit, plus kicking up, along with the lungs (and either SMB or backup bladder) is enough to establish buoyancy. We would be ending the dive at this point and not taking so much more gas out of the cylinders.
We also need to consider that we won't weight ourselves for zero bar, but at something more realistic like 50b for the main tanks. If we used this much gas on the dive, then the deco obligation would not be so high as to need more than 50b from each deco cylinder (plus we would have had something interesting happen to make us go so much over plan).
Additionally, at around 100b the Alu cylinders are neutral and for the maximum bottom time we would get when obeying a minimum gas rule, we would not take more than 50b out of each deco cylinder. If we were in a situation where these deco cylinders did become positive, then we also have the option to ditch those.
I do accept that the total pressure you weight yourself for will change the weights you may want to carry, but at the same time you have to consider all the other aspects when you are making this type of technical dive and what is likely vs unlikely (e.g. to have more than 100b needed of deco gas you had to of overstayed your bottom time by a huge amount etc.).
Lastly, we wanted to keep the idea on the suitability of the dry suit and other methods rather than go into all the considerations of the dive itself - because as you say, that is a bigger subject - and for sure if the wing failed, I would be heading up and not making these kinds of movies at the time :-)
Hope that helps explain a bit more. Cheers.
If you actually paid attention... even in a failed wing you can still hold volume and that helps aswell... long story short.
Ha. Someone beat me to it. There is absolutely NO WAY he is correctly weighted. NO WAY.
@@wowfreaker Rubbish. They've said he's doing it on lung volume alone, with a slightly squeezed suit and empty wing bladder. He's barely negative like that.
So technical divers don't carry weight belt?
BCD failure is rare they are all most foolproof,
He could use his suit as a BCD ,the most gojng yo happen is he gets wet little cold ,but staying 15 minutes at 45 ft then ,decompressed
What about when diving in a wetsuit?
Hi, these are in the other BCD Failure videos - we do them in 1, 2 and 3 cylinders on the same UA-cam Channel. Hope you get a chance to watch them.
How about removing your weight belt and dropping one or two of the weights? Or am I being dumb lol
No need, if you are correctly weighted. As a tech diver, losing the weight is the last thing you want actually.
Because you won't be able to hold your stop higher up....
I dont really get it, you can easy just dive with the drysuit if you want.. its not to recommend.. but its quite easy..
If your drysuit leaks, then what?
From what I can see, it really looks like he have a lot more air in his dry suit than is necessary to compensate for the squeeze... When diving technical you have 2 of everything that is important. This even mean double gear for buoyancy. So this isn't any more special than what's in the training for diving technical.
Yes, he puts more air into his drysuit that is needed that is kind of the whole point in the video, to show in a failure it could be done and still a safe ascent be made. If you watch again and listen to everything we say and example we show it should be clear. Cheers, Steve
Hi, I do not agree with the philosophy of this video because :
- In case of a BCD failure, the buddy can help too
- Having a buoyancy redundancy is compulsory for wetsuit (Tec)divers in areas with downward currents
Sorry, but there is NO WAY that he is correctly weighted. NO WAY.
Air is 1.28g/L. EANX50 is ~1.34g/L
So, an AL80 pumped to 200bar of air holds ~2.84kg of gas.
He's got 4 of them strapped on, thereby got close to 11kg of gas mass (assuming there is no helium involved).
In order to remain neutral throughout the dive he thereby NEEDS 11kg of lift that he can add at the start of the dive, and remove by the end of the dive after the gas in all cylinders has been breathed off.
Looking at how he is with an empty wing and a squeezed suit, there is NO WAY that he is going to be able to stay underwater with 11kg of gas loss by the end of the dive. He's going to pop up like a cork, or wind up having to ditch empty tanks to shed buoyancy.
Turns out a cave diver beat me to it, and has pointed this all out below...
Hi,
Thanks for the comment and thinking about what we are showing.
You are right about the mass of the gas of course. I am using 2 x 12L steel and a 2 x Alu80 BTW (not really related to the total mass) - but we are not weighting ourselves for zero bar, more like 50 bar, so the mass of gas is about 3/4 of the full 200bar fill.
One thing that is often crossed is the idea of lift needed vs weight needed. They are not the same thing. If we need say 8kg of lift for the gas weight, that does not mean we need 8kg of lead.
So we have lets say 8kg of lift needed at the start that we don't need at the end (200 bar to 50 bar usage in 4 tanks).
We then just add whatever weight MIGHT be needed to keep us at 5m with those tanks at 50bar. This amount of weight is nothing to do with what we lost, only what we have at 50bar. And so if I have more muscle, I need less than if I am not as fit. If I am using thicker garments, I need more lead than if I had fewer garments. If I am in Salt, I need more lead than in Fresh.
So the issue is not the weight we lose, but the weight we end up with.
The lift of course depends on the gas weight we will lose - and so we are seeing if I can lift the 8kg using something other than the wing - and of course we already used a bit of gas getting to the wreck, so a little lighter by then too.
Hope that explains a bit more?
Cheers