Water in regulator at depth causing panic

[Salt]

I want to comment on a couple points from the opening post.


The only reason going directly to the surface would kill you would be if you held your breath. You would not get DCS early in a dive like that, and the only reason for an embolism would be holding the breath. I feel strongly about this point. Not understanding this can lead divers to make bad decisions in an emergency.

Is you sequence accurate? You should put it in your mouth first, then press the purge valve. If you press the purge valve before putting the regulator in your mouth, when you stop pressing, more water will go into the valve. When push the purge valve while the regulator is in your mouth, the water is expelled though the exhaust, not into your mouth.

My thoughts in the moment on deciding not to go for the surface

1) I remember looking up and seeing the surface and thinking: “that’s a lot of water to move through. I‘ll run out of air” and drown. Remember I wasn’t operating from a full lung of air. More like 1/4 or less, whatever the residual volume is after a normal exhale.

Would the compressed air in my lungs have expanded, providing access to extra oxygen. The physics says yes. Would it have been sufficient ? I have no idea.

2) Brief flashes to my DAN subscription: something is going to burst in my head or lungs. This was very quick. I was mainly thinking of bubbles forming. Might also have included lungs bursting.

It sounds like the majority opinion here is that due to the brief time underwater there wouldn’t be a lot of gas in the blood yet. So no DCS.

I want to be 100% clear that in that moment I was NOT thinking about exhaling while ascending to avoid my lungs bursting - despite being well aware of this rule from my training!!! The out of air feeling and perception of challenge of making it to the surface was too strong. It is very counter intuitive to exhale precious air when you feel you don’t have enough. Perhaps it would have come to me if my lungs felt full or I was getting more oxygen and that out of air feeling diminished. But more likely I would have held my breath and become another DAN statistic.

One of the points I am trying to make in this post is how easily panic can override rational thought and training - especially if it is something you are just told or have read as compared to a skill that has been practiced. When the **** hits the fan and survival instincts kick in, a lot of stuff goes out the window.

> I think not going for the surface saved my life.

On hitting the purge valve before the reg is all the way in your mouth

You picked up on that. Yes, that is the sequence I did. Not spelled out is that I continued to press the purge valve. No new water entered. It may not be textbook technique but it works. Might even be a hair quicker.

When this event occurred, pressing the purge valve and seeing the bubbles come out in front of me gave me a sense of relief. It told me there was air to be had. I knew I was going to live.

 

[Raphus]

My thoughts in the moment on deciding not to go for the surface

1) I remember looking up and seeing the surface and thinking: “that’s a lot of water to move through. I‘ll run out of air” and drown. Remember I wasn’t operating from a full lung of air. More like 1/4 or less, whatever the residual volume is after a normal exhale.

Would the compressed air in my lungs have expanded, providing access to extra oxygen. The physics says yes. Would it have been sufficient ? I have no idea.

2) Brief flashes to my DAN subscription: something is going to burst in my head or lungs. This was very quick. I was mainly thinking of bubbles forming. Might also have included lungs bursting.

It sounds like the majority opinion here is that due to the brief time underwater there wouldn’t be a lot of gas in the blood yet. So no DCS.

I want to be 100% clear that in that moment I did NOT think about exhaling while ascending to avoid my lungs bursting - despite being well aware of this rule from my training!!! I don’t know if it would have come to me on the ascent or, more likely, that I would have held my breath because I had a long way to go on limited air... and suffered the consequences. I might have become a DAN statistic.

One of the points I am trying to make in this post is how easily panic can override rational thought. That includes training, especially if it is something you are told or read as compared to a skill that has been practiced. When the **** hits the fan and survival instincts kick in, a lot of stuff goes out the window. Exhaling precious air underwater is extremely counter-intuitive.

> I think not going for the surface saved my life.

On hitting the purge valve before the reg is all the way in your mouth

You picked up on that. Yes, that is the sequence I did. Not spelled out is that I continued to press the purge valve. No new water entered. It may not be textbook technique but it works. Might even be a hair quicker.

When this event occurred, pressing the purge valve and seeing the bubbles come out in front of me gave me a sense of relief. It told me there was air to be had. I knew I was going to live.

I am a little bit confused about the oxygen part..
Po2 increases as pressure increases.
If you go up the volume of your 1/4 lung will increase. So you might have a half full lung (eg. Going from 30 to 10m), but the po2 is half.

The amount of oxygen is the same! (Minus some oxygen lost, because of blowing bubbles)
But the po2 is lower. Which kinda means the availability of the oxygen.

Example: 30m depth. Po2 of 0.21 which is the equivalent to the po2 we have at the surface.
You ascent to 10m. Your po2 is now half. So around 0.1, which is too low. You will probably fall asleep and never reach the surface.
But you could stay at 30m for a bit longer. Because of the higher po2.

So volume, oxygen units and po2 are 3 different things, but are all linked to each other.

Thanks for sharing your incident. Practice reaching your octopu, because it is a fundamental skill for diver's.

 

[SysGreg]

? Maybe a sidemount thing?

Normal rec procedure when entering water is palm/heel of hand over reg and fingers over mask. This is from The Easy In: Tips for Performing the Giant Stride Entry - Dive Training Magazine | Scuba Diving Skills, Gear, Education

Nice pic, but remember you have two heavy tanks on borh sides connected just with a clip and bungee. You need to use both arms to squeeze tanks to your body in order not to hit you when entering the water. The arm becames “too short” to effectively cover the tanks, mask and reg. And as I said earlier, probably the reg flown away when ascending and gas was on the way out. at that moment you do not hold a mask nor regulator anymore. Anyway, lesson learned.

 

[lowwall]

Nice pic, but remember you have two heavy tanks on borh sides connected just with a clip and bungee. You need to use both arms to squeeze tanks to your body in order not to hit you when entering the water. The arm becames “too short” to effectively cover the tanks, mask and reg. And as I said earlier, probably the reg flown away when ascending and gas was on the way out. at that moment you do not hold a mask nor regulator anymore. Anyway, lesson learned.

So it is a sidemount thing. It wasn't mentioned in the post I was responding to. I just traced it back and you did mention it on the second page of the thread.

I don't know anything about sidemount, so I won't presume to comment on SM entry techniques.

 

[GJC]

I am a little bit confused about the oxygen part..
Po2 increases as pressure increases.
If you go up the volume of your 1/4 lung will increase. So you might have a half full lung (eg. Going from 30 to 10m), but the po2 is half.

The amount of oxygen is the same! (Minus some oxygen lost, because of blowing bubbles)
But the po2 is lower. Which kinda means the availability of the oxygen.

Example: 30m depth. Po2 of 0.21 which is the equivalent to the po2 we have at the surface.
You ascent to 10m. Your po2 is now half. So around 0.1, which is too low. You will probably fall asleep and never reach the surface.
But you could stay at 30m for a bit longer. Because of the higher po2.

So volume, oxygen units and po2 are 3 different things, but are all linked to each other.

Thanks for sharing your incident. Practice reaching your octopu, because it is a fundamental skill for diver's.

Oxygen is also consumed by your body, so the longer you dont breath, regardless of depth, the lower it goes in your lungs. So if you are breathing air not nitrox, most of your lung expansion is nitrogen and your lungs will have very little usable oxygen after just a few minutes,

You also need to consider CO2 production by your body. Increased levels in your blood is the first thing that triggers your body to take a breath, even if O2 is at 100%.

 

[brownie]

We taught our students to dry breathe each reg before turning on their gas. The reg should be air tight. I never see other divers do this.

Thank you @rick00001967 for sharing this--and thank you also to other posters who have raised the same issue. I was not taught to "dry breathe each reg before turning on the gas" in my scuba training; but will adopt this practice in future dives. Always something to learn on Scubaboard!

 

[johndiver999]

Thank you @rick00001967 for sharing this--and thank you also to other posters who have raised the same issue. I was not taught to "dry breathe each reg before turning on the gas" in my scuba training; but will adopt this practice in future dives. Always something to learn on Scubaboard!

FYI you want to suck gently, if you go overboard, you can cause the exhaust to fold in. Just a gentle vacuum like drinking from a straw.

 

[brownie]

Duly noted @johndiver999 thank you.

 

[berndo]

Example: 30m depth. Po2 of 0.21 which is the equivalent to the po2 we have at the surface.

On air the oxygen pressure is .44 .84 at 30m. The o2 % is .21.
Doesn't really matter, when someone does an emergency ascent it's just about making to the surface. This whole side discussion about partial pressures doesn't really matter in this context.

You ascent to 10m. Your po2 is now half. So around 0.1, which is too low. You will probably fall asleep and never reach the surface.

Partial pressure is what matters, not %. I think you got something mixed up.

Edit: not .44 but 0.84

 

[berndo]

Nice pic, but remember you have two heavy tanks on borh sides connected just with a clip and bungee.

You can hold the top of the tank down with you're elbow so is doesn't get pushed up when you jump in.