Equipment My first out of air situation

[ispasov]

Hello fellow divers. I'm a newcomer to the diving hobby. I got OW certified this year and have only 30 dives .On my 30th dive I experienced an out of air situation. Please help me understand what happened and if I did something wrong.

I am a very cautions about my air consumption and normally I check my air once every couple of minutes. Here is what happened:

I was in a group of 6-8 people diving in Greece. At about 30 minutes from the start of the dive I checked my air and I had around 110 BAR. We were at 22 meters. Couple of minutes later we spotted a nice octopus and I was checking it out and having a super nice time. At about minute 35 I noticed that taking a breath started to require a lot of effort, like something was blocking my hoses. Looking at my computer I saw that I only had 3 BAR left . I immediately went to the dive master and gave him the out of air signal. He understood me and double-checked my computer. He offered me his backup 2nd stage, but I didn't take it immediately, because I was still breathing (harder and harder, but still doable). We slowly started going up. I positioned myself very close to his octo, so that in case I run out of air completely I can grab it relatively quickly. I wasn't in panic at all, but I still had a strange feeling of uncertainty. Shortly after, I ran out of air completely, gave my DM the signal again and he passed me his octo. So far so good, I was finally able to take a normal breath. We continued going up, but from time to time we had to stop and wait for the others, because we were in a very bad visibility. We made it to around 5 meters and we started our safety stop. During the stop I passed him my primary so he can double-check if I was really out of air (by then I was still thinking that maybe I was doing something wrong). He confirmed. At minute 2 of the safety stop I had the same feeling again - taking a breath required a lot of effort and I was not able to take a full breath - clear sign the DM's tanks was running low. We finished our safety stop. By the end of it there was no air inside the tank. That was no problem, we ascended safely and I remembered to blow bubbles on the way up (huge thanks to Gus and Woody from Dive Talk).

I am loosing sleep over what actually happened. Maybe something blew up and all of my gas went out. I don't think so, because I expect such event to be noisy. I didn't hear that. I am a beginner diver and I am working on my trim a lot. That day I noticed that when I was adjusting my trim (upper body going up or down) I was hearing bubbles going out. I was thinking that these were not bubbles, but rather the air inside my BCD moving (how stupid was I....). That happened multiple times. I believe that's how I lost my air. However, these adjustments were happening over a period of time. According to my computer I lost my air in a very short time. I don't know what to trust - what I heard or what my computer is telling me. According to the DM it was sort of malfunction in the regulator, because it was due for a service. I am confused I am also wondering if I tightened the 1st stage to tank good enough. These were DIN tanks.

What do you think? What possibly happened that day? Have I done something wrong and what can I do to reduce the risk of that happening again? I am buying a set of personal regulators so that I can be responsible for cleaning and maintaining them.

Here is a photo of the air chart for your reference:

 

[rongoodman]

First, the safety stop is optional. If I was bringing up somebody who was out of gas I would not pause for one. It sounds like you kept it together otherwise, so that's good. Had you been losing enough air during the dive to matter you or the other divers would certainly have noticed--it isn't a subtle thing. Looking at the computer graph I'm wondering if the dip tube in your tank became plugged or there was a blockage of some sort in your first stage regulator which caused the sudden drop in pressure. The only way to know would be to tear down the regulator and remove the valve from the tank for an inspection.

 

[DevilEyeDog]

Hello! Welcome to the wonderful world of diving. Having experienced an O-ring that exploded underwater, resulting in the sudden drop of air, I can assure you that you would know if all of a sudden your tank was draining. Usually, there’s some type of loud noise and obvious gas escaping.

What you have here as a situation of new diver and the excitement of an octopus. . Marine critters were very exciting and that will cause you to breathe a lot faster and heavier. You are moving quicker without realizing it. You are excited and your breathing will reflect that.

Marine life causes us to suck down more air but with time you will learn to relax. You will learn to calm down around marine life which allow you more opportunities to enjoy them.

Good news is you did everything right!!! . Most newer divers would have failed but you did all the right things.

It comes a little surprised that on your way up you also drained your Dive masters tank. Nervousness will do that!

I’m super glad you were here to report everything. My best advice is to realize that you need to improve your air consumption and relax when you see marine life and really really pay attention to it!

 

[boulderjohn]

I don't have an opinion on how you lost that much air that quickly, but I can give you some information that may help your overall understanding of the situation as a whole

When we say a tank is out of air, it is not really out of air. In order for you to breathe air during a dive, the air must come to us at a greater pressure than the water pressure at our depth. Your ability to breath is a result of a combination of the pressure in the tank, your effort to inhale, and the way the regulator works to assist the process (it mechanically adjusts to the water pressure at that depth). As the tank pressure gets too low, you will have to work harder to get the air into your lungs. That is why it got harder to breathe at that depth.

As you ascend, the water pressure drops, and it will get easier to breathe, and then it will get harder again as the air pressure drops further. As you experienced, eventually it will stop, even at a very shallow depth.

You are to be commended for staying calm all the way to the end of the experience. I case you get into a situation like that with no one else to share air nearby, here are some facts you might want to keep in mind.

• On a NDL dive, the safety stop is not required. It just gives an extra margin of safety, but you should be OK without it.
• If you had started to ascend at a normal rate when it got difficult to breathe and you saw your gauge was that low, you probably would have made it all the way to the surface breathing normally, since the regulator could have given you air as the water pressure became less and less.

 

[ispasov]

What you have here as a situation of new diver and the excitement of an octopus. . Marine critters were very exciting and that will cause you to breathe a lot faster and heavier. You are moving quicker without realizing it. You are excited and your breathing will reflect that.

Thanks for your input, but I slightly disagree. To me octopuses are super interesting animals and every time I see one I get excited. However, I don't think I got so excited that I took 100 BAR in just a moment. My lungs don't have that capacity. Please check my graph. It was a sudden drop of pressure.

 

[gamon]

How in the world would a DM allow both of you to run out of his gas supply? And continue the safety stop to completion from the 2 minute mark despite both of you drawing hard on the last gas in the tank and the dive being relatively shallow?. How in the word did neither one of you know to grab the DMs octo given that you were obviously drawing the last few breaths of available gas from your tank?

And why would you pass the primary to check if you "were doing something wrong" despite you knowing your tank was empty as you had checked the pressure? You've got at least 30 dives...

How many newly minted divers use air integration anyway?

It's unbelievable.

 

[ispasov]

How in the world would a DM allow both of you to run out of his gas supply? And continue the safety stop to completion despite both of you drawing hard on the last gas in the tank.

And why would you pass the primary to check if you "were doing something wrong" despite you knowing your tank was empty as you had checked the pressure?

It's unbelievable.

His tank got empty at the end of the stop. The safety stop is not bothering me that much. I believe he did the right thing. I'm trying to understand what happened and how I ran out of air on the first place.

I passed him mine for verification, because I am a newbie and I was having second thoughts that I was doing something wrong

 

[davehicks]

It does sound to me like your tank valve was not fully open. Did you check this at the end of the dive or on ascent? This is fairly common with new divers. If the valve is not 100% open it can stop flowing air prematurely once you reach a certain depth or lower tank pressure. Did you check this?

 

[stepfen]

One good question is, after the dive did the tank contain any gas?
I would guess so.
To me the only possible way of suddenly "loosing" ~100bars of gas is something blocking the flow. Either something clogging the filter or the dip tube (if there was any) or something similar. Physically it is not possible to loose that much gas without noticing. We are talking about a lots of gas here...

 

[stepfen]

It does sound to me like you tank valve was not fully open. Did you check this at the end of the dive or on ascent? This is fairly common with new divers. If the valve is not 100% open it can stop flowing air prematurely once you reach a certain depth or lower tank pressure. Did you check this?

Not possible either. If this was the cause once they started ascending his flow would have resumed but according to his description the DM tried the OPs first stage during the safety stop and it delivered no gas. The pressure graph would also show this (pressure would fluctuate for every breath up and down) .