New safety protocol? loosen weight belt AND remove mask?

[harbour seal]

Hey guys,

a question/discussion about safety protocols for ascending from a difficult dive (one where we are worried about BO'ing):

1. loosen and hold weight belt in one hand (or) ditch weight belt
AND
2. remove mask and hold in hand (expose face)


currently, removing the weight belt and holding it in one hand during the ascent is a part of a diver's safety protocol. the idea being if the diver were to BO then they will (hopefully) float to the surface (this assume the diver was positively buoyant at the BO depth). also completely ditching the weight belt will help save energy on ascent.

in a recent thread on SWB, sebastian murat suggested removing the mask when one is worried about BO during the dive. exposing your face will help strengthen the body's oxygen conserving mechanisms. [see link and sebastian's post below]

so my question is should we now use BOTH of these strategies when ascending from a hard dive?

seems reasonable but i would like to hear what the experienced divers have to say. will definitely be something that needs to be practiced.

cheers,
sean
vancouver



here is the link (i highly recommend the thread as there is some excellent discussion):

http://forums.deeperblue.net/safety/71040-swb-reducing-risk.html


SWB: Reducing the Risk


Here's a free tip without all the physiological mumbo-jumbo:

If you think/sense you're not going to make it simply remove you mask, pull your hood back somewhat, take off any nose-plug, or whatever is covering your face, upon initiating your ascent. This simple act will magnify your O2-conserving dive response when you most need it, on the way up reducing the risk of a BO.

Seb

PS: this technique can also be used to minimize the risk of a BO in the latter part of any static or dynamic dive, by the way.

 

[Veronika]

Hi Sean,
for me the answer to this is a clear "no":

- remove weight: would add additional taskload and physical load. Apart from that, I think it is quite uncomfortable to hold the weights asymmetric (not having them around the body center). I do not think this is a good idea.

- drop weight: Wouldn't want to ditch my weight in a deep quarry if I don't have to. IMHO that's the ebst way to lose it. Apart from that, it's "Constant" weight after all?

- remove mask: Wouldn't want to do this in 4°C water. Apart from that, as much as I appreciate Sebastian Murats spirit of innovation I'd like to see the concept scientifically proven before I'd incorporate it in a surface protocol.

Just my 2cents worth, though.

All the best,

Veronika

 

[shoutatthesky]

What is your life versus the cost of a weight belt???

Removing your mask in 4C water? No big deal - a nice cool reviver where it is needed(on your face).

 

[harbour seal]

hi veronika,

you bring up many good points but the main issue i wanted to discuss was the feasibility of using BOTH of these techniques together (which wasn't clear).

also, i think you might of missed the point of these procedures: use in case of EMERGENCY---they may be inconvenient but would you rather BO?

Hi Sean,
for me the answer to this is a clear "no":
- remove weight: would add additional taskload and physical load. Apart from that, I think it is quite uncomfortable to hold the weights asymmetric (not having them around the body center). I do not think this is a good idea.

removing the weight belt this is not something you should be doing on every dive BUT in case of BO risk/low oxygen situations. at this point "comfort" should be the last of your concerns. actually, this is a well known procedure you should consider adding to your repertoire through practice.

- drop weight: Wouldn't want to ditch my weight in a deep quarry if I don't have to. IMHO that's the ebst way to lose it. Apart from that, it's "Constant" weight after all?

again, only in dire circumstances would you drop the belt. personally, when in serious risk of BO i say screw the belt.

- remove mask: Wouldn't want to do this in 4°C water. Apart from that, as much as I appreciate Sebastian Murats spirit of innovation I'd like to see the concept scientifically proven before I'd incorporate it in a surface protocol.

nor would you be frequently removing the mask during a dive BUT instead only in cases of BO risk. cold face or bo? hands down i go for cold face. also the oxygen conserving effect on the body will apparently be STRONGER with cold water.

certainly you make a valid point about a new technique and i fully agree that it should undergo wider testing----HOWEVER, personally i will always do everything possible NOT TO BO when i in danger no matter how "uncomfortable" or unpleasant the technique.

additionally, you mentioned "work load", which is really what i am wondering---will it be feasible to perform BOTH of these tasks in a hypoxic state? (perhaps train yourself to do one with each hand?)

cheers,
sean
vancouver

 

[harbour seal]

What is your life versus the cost of a weight belt???

Removing your mask in 4C water? No big deal - a nice cool reviver where it is needed(on your face).

nice one, you beat me to it and managed to say everything i did to boot!

cheers,
sean

 

[island_sands]

I wouldn't remove my mask, for risk of water inhalation and also remember monkey see monkey do, someone else might see you doing it and then panic, inhale. You dont have visibility with your mask removed and may become disorientated. Also why would you want to expend even more precious energy and O2 by removing your mask?

One person's "new safety protocol" doesn't necessarily mean it's gospel. all that you read on Deeperblue ain't gospel either.

 

[trux]

OK, me too:

- remove weight: would add additional taskload and physical load.

That's exactly why it ought to be drilled. Once it is automated, it adds no stress. I do it routinelly when diving alone (though I know I should not dive alone).

Apart from that, I think it is quite uncomfortable to hold the weights asymmetric (not having them around the body center). I do not think this is a good idea.

Not at all unconfortable. You just release the buckle and keep your hand on it. In case of BO it slips away and the belt falls alone.

- drop weight: Wouldn't want to ditch my weight in a deep quarry if I don't have to. IMHO that's the ebst way to lose it. Apart from that, it's "Constant" weight after all?

If you worry about your weight belt, you will simply never drop it. It means it is worthless as a security measure. Have always a second belt in your car or home ready - that will remove the psychological barrier. Or have it attached to a float.

- remove mask: Wouldn't want to do this in 4°C water. Apart from that, as much as I appreciate Sebastian Murats spirit of innovation I'd like to see the concept scientifically proven before I'd incorporate it in a surface protocol.

It was already scientifically proven many times. Have a look for example at this document: diving response @ APNEA.cz Especially the last document listed there, shows the effect of facial immersion in laboratory conditions rather clearly, and it also lists many useful links and referrences.

 

[jome]

Regarding the weight belt

For recreational diving, I would say you should not be diving anywhere close to such performances you ever need to be worried about BO. But if that makes you feel better, why not.

For CW with a descent line and safety divers, I would say no. If your dive is going to be close, you have much better use for your hands than holding a weight belt. Such as grabbing the rope/float. And most divers are balanced so that they will float from the "risky part" anyway, so I see no point.

 

[island_sands]

It was already scientifically proven many times. Have a look for example at this document: diving response @ APNEA.cz Especially the last document listed there, shows the effect of facial immersion in laboratory conditions rather clearly, and it also lists many useful links and referrences.

Facial immersion has been recommended yes, but face down on the surface before a dive, not while you are just about to die underwater from a BO.

Kirk and Mandy teach it in their courses and it relaxes you, assisting your mam. reflex to kick in. Laboratory conditions are always theoretical, Sean ascending from a dive, possibly a deep dive, on the verge of blacking out and then removing his mask is possibly going to relieve him of his DB membership

 

[trux]

It does not really matter whether it is during static or a deep dive. The reflex is based on the facial thermo-receptors, and the effect is almost immediate. It does not need to be before the dive only. And since typical diving mask covers significant part of the face, removing it will definitely have positive effect. Well, if you already dive with just goggles, then it won't have any big impact, but otherwise it may indeed help. I agree though that I wouldn't recommend it trying just when you are in an imminent threat of BO - you must be used to do it relatively automatically, so that it does not cause more harm than good.

And to Jome - yes, I believe we discuss here recreational, exploratory freediving or spearfishing. It is certainly more or less pointless for competitive freediving. And yes, normally you should never need it, but you never know - if you get tangled or have any innexpected situation, having drilled such methods regularly may save your life. If you do not release the weight belt buckle automatically at most dives, you will certainly not think about it when you are in panic.

 

[Veronika]

Sorry guys, misunderstanding (thanks for clearing that up, sean). "Safety Protocol" implied for me to do it regularly (like a surface protocol) thus I wondered why you would want to remove your weightbelt as standard procedure. We all know that in an emergency dropping the weight is priority #1. But then I wouldn't hold but drop it.
I might be a weenie, yet for me, 4°C is disgusting. I did it a few times and it felt like being hit in your face. I' thus prefer not to do it since I don't know if it would help being relaxed, but then again, that's a personal thing.

Ok, gotta go, still wanted to answer - will be back l8er,

thx,

Veronika

 

[laminar]

The only problem with performing either of these steps is the assumption that you will be clear headed enough to actually do them when it is needed. If you are scared and already on your way up and thinking that you might not make it, you probably wouldn't want to remove your mask. Maybe you'd think about the weightbelt, but only if you practice undoing the buckle on a regular basis as practice. If you never do it, you certainly can't rely on doing it when things get hairy. I much prefer practicing making safe and conservative recreational dives.

I really feel (from my experience as a safety freediver) that on a really close dive, especially on a line, most people are too "out of it" to think about releasing their weight belt, let alone undo the buckle and then hold on to it, which takes some effort, depending on the weight belt and amount of weight. Also, if you have a weight belt with a belt buckle enclosure, it will be more difficult to do this quickly.

The only time I would really plan on doing such a thing is if I had to rescue a buddy from the bottom and knew that I would need all the buoyancy to help us both reach the surface.

If anyone decides to use weight belt release as a safety measure, then I would suggest releasing the belt buckle on every deep dive to make it automatic, otherwise the odds on not doing it are against you.

Pete

 

[trux]

Yes, Pete, I totally agree with you that it is better (and necessary) to watch that you never get in such situation, and also that when you then need it, in the panic you won't think about about dropping the belt or removing the mask. That's why I wrote you should drill it at every just little bit longer (though still largely safe) dive. When it becomes an automatism, you have better chance it helps you when you really need it.

I admit I do not remove my mask (or did not yet start trying to do it), but I do regularly open my belt buckle when ascending from any deeper or longer dive (say in about 50% of cases). It became so automatic that I do not need to think about it, and it does not cause any discomfort.

 

[harbour seal]

great discussion everyone!

exactly the kind of feedback i was hoping for, especially from such experience and knowledgeable divers.

just to be clear, we are not discussing pushing our limits and then employing these techniques as a fail safe or backup. of course it is always better to concentrate on diving well within ones limits BUT in the case of an unexpected hairy situation what is the BEST way to stave off BO and get yourself to the surface?

If anyone decides to use weight belt release as a safety measure, then I would suggest releasing the belt buckle on every deep dive to make it automatic, otherwise the odds on not doing it are against you.

good advice! trux, sounds like you already do this---do you think you could feasibly remove your mask as well?

@pete - really appreciate your feedback from the perspective of a safety diver.

if one were to use the mask technique as well it certainly would have to be drilled and drilled until it could be done automatically.

I wouldn't remove my mask, for risk of water inhalation and also remember monkey see monkey do, someone else might see you doing it and then panic, inhale. You dont have visibility with your mask removed and may become disorientated. Also why would you want to expend even more precious energy and O2 by removing your mask?

One person's "new safety protocol" doesn't necessarily mean it's gospel. all that you read on Deeperblue ain't gospel either.

island sands - unprotected airway is one of the main concerns i have about this technique as well. personally, i don't worry about the vis issue as i have done lots of swimming and diving (shallower) without a mask.

BUT regarding the energy expenditure it sounds like you might actually SAVE oxygen overall by getting it off, which is why i want to flesh out the practicalities of this technique.

QUESTION: do you folks think that removing the mask (and exposing the nasal passages) is an additional risk to water inhalation when in a near BO situation (or other risk)? isn't this risk already present via the possibility of water inhalation through the mouth? is it much greater with the mask off (or for that matter diving without a mask)?

cheers and thanks for all the input.
sean
vancouver

 

[Fondueset]

My impression re-the mask suggestion was that it be implemented if you really feel you might about to lose it. The weight belt suggestion could easily be done with a standard quick release buckle. Just flip the buckle and hold the belt together with thumb and forefinger.

Of course the best thing is to practice safe diving - and surface well-within the easy range. I've pretty much decided, in the absence of really competent buddies watching me, I'm going to assess my dives according to the 'max-easy' criteria.

 

[efattah]

Having had many dives with sambas and several blackouts, including one samba on a recreational dive in 2002, I can say first hand what happens in these situations.

Even for someone with great experience with hypoxia, you will never realize that you are in trouble until you reach a shallow depth. If you really overdid it, you may realize you are in trouble at a depth of around 15m, but usually you'll realize it around 10m or less. Once you realize that you are in trouble, you have about 1 second of useful consciousness, which is not enough to do any task. Once that one second elapses, the only thing you will do is continue kicking towards the surface, in a virtually unconscious state.

Even if taking the mask off had an oxygen saving effect, this oxygen saving effect would have be IN EFFECT for at least 10-20 seconds of dive time to actually have a noticeably positive effect. But, you need to SUBTRACT the energy of actually removing the mask (and holding it hard clenched in one hand, which is what you would likely do). Not to mention the total loss of velocity caused by the drag of doing it. In my opinion it would be detrimental.

I did a 'dumb' solo freedive in 1998 to 31m with a big weight belt and bifins. On the ascent, I realized I was in trouble around 15m, and my last clear thought was 'I should ditch my weight belt.' The next thing I knew, I was at the surface and my vision was gradually returning. I was still wearing the weight belt.

By 2002, I was much smarter. After having already set a WR and having had blackouts at the end of dives, I realized what I should really be thinking when in trouble. I did a shallow dive on a wreck (23m) for a very short total dive time (1'30"), but my recovery had been far too short from the previous dive. On the ascent I suddenly realized I was in trouble around 15m. I knew I had one second of useful consciousness. I used that one second to tell myself one thing: Remember to breathe upon surfacing!! I reached the surface in a virtually unconscious state, but I took a deep breath, and had a big samba. My buddy was 30m away pointing in a different direction. If I had tried to ditch my weight belt, I would probably be dead.

In my mind, the only time it is conceivable to ditch the weight belt with benefit (or remove the mask), would be if you got stuck in something on the bottom (wreck, fishing line, etc.), and you overstayed your bottom time and realized you had been on the bottom for WAY too long. Even before beginning the ascent, you decide that you must ditch your belt and remove your mask. You don't lose any momentum or cause any drag, because you aren't even moving yet.

 

[laminar]

Practicing mask removal over and over again may lead to a reduced "life-saving" effect. Seb Murat might have some insight on this. If it starts out being a stressful event, long practice would tend to make it comfortable. Seb experienced this desensitization effect during his high-stress training program.

Overall, I really don't know how practical removing your mask is on the way up. The loss of vision, inability to judge how close to the surface you are, panic, feeling of drowning and having water in your nose/sinuses (possible sucked in my involuntary contractions), inability to see obstacles to your surfacing, makes for a messy surfacing. There is also value in having your nose airway sealed off from the water should you black out on the surface. Ideally, your buddy sees you in time and can assist you even if you loss consciousness on the surface. If your nose is exposed, water is more likely to jeopardize the airway before and after consciousness is regained.

I could see the O2 saving benefits of removing the mask (if all other stress factors didn't counter them) on a deep line dive near max.

Better yet, dive without a mask in the first place from start to finish (or use fluid goggles).

I think the best way to prepare for a hard dive is to practice on a line. But then again, practicing on a line means you are perhaps more likely to go deeper than you should recreationally. Personally, I prefer baby steps in recreational diving, ending dives before contractions (once you are knowledgeable about your own physiology and your personal symptoms of overbreathing), and not diving by the gauge/watch.

 

[Fondueset]

Since I finally sold my soul and got something less than an F1, I've been pleased how useful a guage is. I use it for basically two things - reviewing my dives when I'm done - and enforcing decent surface intervals.

(my daughter PREFERS to dive with no wetsuit and no mask - just a monofin. once the temp is about 16c the suit is gone)

 

[trux]

Waiting till you feel you are in troubles, is of course nonsense. You have to do some countermeasures far before. That's exactly why I am telling I am opening my belt buckle at any dive longer than some 40s. And I do it preventively at the bottom, I do not wait to see if I can make it up first.

I realize that removing the mask is less practical, but you could probably drill yourself for doing it when starting the ascent too. Once you are used doing it regularly, it won't be too inconvenient. Finally when ascending, the vision without a mask should be rather sufficient. Better than removing and keeping in the hand is probably pulling it down to the neck, or maybe keeping on the front - some additional fixation might be wise though, to avoid losing it.

 

[naiad]

I am not too sure about the whole dive reflex thing. For me, cold water on my face, or being in cool water, reduces my apnea time and increases the risk of blackout. I am not sure why this is, but it has consistently proven to be the case for me.