Out of air under 20 meter after 30 mintues of 10 to 25 meter drift diving

[BKP]

Don't the agencies have ultimate responsibility for the minimum quality of their instructors?

In theory, I suppose they do...

However, giving two well-intentioned hosts the same instructions, and shakers, doesn't guarantee you're going to get the same cocktail...

 

[JerseyBoy]

The essence of remaining within the no deco limits is that a direct ascent to the surface is possible at any time, so long as you don't exceed the ascent rate programmed into the tables. For the PADI RDP, that ascent rate is 60 fpm. So long as you took a full minute to reach the surface, and exhaled the whole way, the likelihood is that you would have been fine.

I think you learned your lesson about checking your gas -- but there are a couple more lessons here, too. You went to the DM for gas, which implies to me that you either did not have a buddy, did not know where your buddy was, or could not reach him. You just learned why buddy teams need to stay close to one another, even when the viz is good. If your spare gas is on somebody else's back, you need to keep that back where you can reach it!

Second, if I am reading your story correctly, the DM to whom you went for gas ran out on ascent as well. What does that mean? It means that he did not retain enough reserve gas to get two people to the surface from where you were. How much gas it that? There are actually ways to calculate it (HERE is a good article on that), and a prudent diver never empties his tank more than that, because you never know when you might have to help someone else. You are not at fault for not knowing about this, because it is not taught in the recreational curriculum of many agencies. But now you know -- plan your dive; you should know what the maximum depth expected is, and you set aside enough gas to get you and your buddy to the surface from there.

Glad you were okay, and thank you for sharing your experience so that other people can learn from it. It takes a rhino hide to admit error here, sometimes.

You have raised good points. Fortunately, my shop's guide had enough to float both of us close to the surface over the course of 1 minute. It was very short time because I remember my dive computer indicated I was under water for 30 minutes (I was checking my dive computer when I noticed I am not getting enough air from my regulator) and the final dive time shown on my dive computer was 31 minutes. The tank was a 10 liter aluminum I believe. The pre-dive pressue was 190. I believe my guide's tank is exactly the same. Due to some heavy use of BDC and air in the occasional fast currents (the spot is in Mikomoto, Izu, Japan), I think the guide had barely enough air for himself. Good thing is this dive location's rules is 30 mintues dive and 5 mintue of safety stop at 5 meters. So, when I ran out of air, it was exactly the time the whole diving team was about to float upward.

I had a buddy; but, I was diving with a commercial shop with a guide. So, I am not even sure if this buddy of mine set up before I board a boat that morning is aware of what to do.

I see many people raising issues with my fin-kicking. The dive spot is famous for the hammer head sharks and divers sometimes use fin-kicks to get moving if the said attractions are not in the down stream of the current. This is the only dive site so far I use air rather quickly than any other places I ever dived (Palau, Saipan, Izu, & Okinawa)

In hindsight, I should have floated a few more meters up to lessen my fin kicking as there was some down current to reduce the air consumption.

Since my dive histroy is rather short at about 14 months, my memory of advanced open water and rescue courses are still there. The reason I posted this question was to know what the real world implication would be because the training and textbook are done in the controlled environment. It was a scary thing to find out the air guage is showing zero air, I can attest to that.

 

[ThomasScherrer]

accending at 9m/min is the normal max speed on many computers, halve of worst case allowed 18m/min.
so this means it will take 2 mins to surface up from 20m, and this is with no safe-stop offcourse.
at what cause is this performed in real life ? as a standard thing the students must be able to perform ?

 

[JerseyBoy]

free accents was practised from 6m at my OW
and from 10m at my AOW course, dont know about rescue, since I did not compleete that one yet. (will do next week)
free accent from 20m is a bit more critical due to DCS, so training and good help could be needed here,
if you know how to do it, and you know for sure you can actually perform it,
then there is nothing big to be affraight of, and less reasons to panic.

As you said, the fact I was aware I was 20 meters deep at that parituclar moment (prior to that moment, I believe I was somewhere between 20 and 25 m) made me unnerved. If I were at 10 meters or so, then, I would have just floated upward saying Ahhhh. thingy exhaling air during an emergency ascent. In a way, I was lucky I was able to acent over the course of 1 mintue close enought to the surface with air from the guide's octopus and that was the first dive of that day. If it was a 2nd or 3rd dive of that day, then, such an ascent "could" pose a problem.

 

[ThomasScherrer]

amazing people dive after minutes of time,
and not after actual air consumption or worst case calculations,
a 10L tank and 20 m deep, you can empty it in 20mins if you work a bit and is avarage sized,
another thing is you and your buddy must leave for surface in good time, so you have plenty of air to help others,
in case some bad things happen.

 

[ThomasScherrer]

you do empty BC a bit while you accent, right ?
if not you rocket to surface, you dont want that.
this air you let out, you can breathe it !
if this is last option, I rather go for wierd smelling bc air, over sucking in water, on my way to surface.
but how many thinks about this in OOA events ?
and how many have actually practiced this under safe conditions, so they know they can perform it ?

 

[TSandM]

It makes me very sad to read, if I am interpreting correctly, that although you had a "buddy", you dismissed this person as a resource and were not even sure if he would know what to do in an out of air situation. Did you guys not do a buddy check and discuss a dive plan? I realize that doing such things is rare (at least in my observation of people on boats in a variety of places in the world) but it WAS taught to you and really should be done. Each buddy team should inspect one another's equipment in order to know how someone will go about donating gas, and how someone would drop weights; if you don't do that, you probably CAN'T expect your buddy to be of assistance. But as you found out, the DM may not be much, either. I do find it utterly inexcusable that the DM did not have enough gas to get you both to the surface. If he can't retain adequate reserves on the tanks available from his employer, he should be in doubles or carrying an auxiliary. It is CERTAINLY a foreseeable problem that a DM might have to get an out of gas or low on gas diver up -- he should be prepared to do that. But again, EVEN IN THE PROFESSIONAL curriculum of at least one major agency, gas management is not taught.

 

[dumpsterDiver]

It makes me very sad to read, if I am interpreting correctly, that although you had a "buddy", you dismissed this person as a resource and were not even sure if he would know what to do in an out of air situation. Did you guys not do a buddy check and discuss a dive plan? I realize that doing such things is rare (at least in my observation of people on boats in a variety of places in the world) but it WAS taught to you and really should be done. Each buddy team should inspect one another's equipment in order to know how someone will go about donating gas, and how someone would drop weights; if you don't do that, you probably CAN'T expect your buddy to be of assistance. But as you found out, the DM may not be much, either. I do find it utterly inexcusable that the DM did not have enough gas to get you both to the surface. If he can't retain adequate reserves on the tanks available from his employer, he should be in doubles or carrying an auxiliary. It is CERTAINLY a foreseeable problem that a DM might have to get an out of gas or low on gas diver up -- he should be prepared to do that. But again, EVEN IN THE PROFESSIONAL curriculum of at least one major agency, gas management is not taught.

It is sad, but it is just one more anecdotal story that indicates that even traveling/vacationing divers might want to consider a pony bottle. Apparently the OP, the dive buddy and the DM were all pushing the limits so far that they couldn't complete the dive safely.

How many new divers go to a resort and end up relying on the DM to get them out of trouble? It is a false confidence. Even the most inattentive diver (the OP) would probably realize that when it gets hard to breath, it is time to check your air, switch to a pony and consider moving toward the surface.

These are the kinds of incidents that result in double drownings.

 

[farsidefan1]

Thanks for posting. My first thought was where was your buddy. That has been covered now but it brings to mind what to do when you are that solo diver on vacation. I handled it poorly on my last solo venture. I was in Palau without my usual dive buddy - she was in Japan playing with new grandaughter - so I was just "assigned a buddy on the liveaboard. Shortly before we went in my "buddy" came up to me and said, "my idea of a buddy is one who is in the same ocean I am in and comes up the same day" or something to that effect. Instead of going to the captain and requesting a buddy who was not already buddied up to his photographic equipment I simply said fine and proceeced to do my own thing (In case no one else thinks this I will say it. It was stupid). My reasoning was this. Conditions were warm tropical water with excellent visability, I check my gear carefully, I planned on staying near the divemaster, I have done several solo dives in which I follow several limiting guidelines, so it did not seem to be a big deal. Which it wasn't - as long as the poop did not hit the fan. The tricky thing about unexpected freak events is that they are, well, unexpected. Lesson learned for me is simple. Have a good talk with new buddy when in similar situation and come to an understanding, vigorously explained, of what I expect to be able to provide and what they are expected to do. If they have a problem with that, fine. I'll find someone who will or I'll explain to the dm the situation and that I will be within a few kicks of him/her. Part of me is resitant to that simply because of the good fortune Ihave had in not experiencing an unexpected catastrophic equipment failure of my gear or my buddies so I have not had that OH SHOOT type of experience to tap into when I need to be more firm about buddy behavior and what I expect. In my defense I am a bit of a computer watch nazi. I doubt I have ever gone 10 minutes without checking my air, depth,remaining bottom time and so forth. Still this post has been usefull to me in motivating a change in dive protcal. Thanks again for posting.

 

[eelnoraa]

I do find it utterly inexcusable that the DM did not have enough gas to get you both to the surface.

I am totally with you on this one. As a dive guide, I assume a paid professional with enough experience of his/her local water, should call the dive with his air reach min reserve level. And he/she should know the min reserve level is NOT only to cover himself but also another diver to do a safe ascent & safety stop(s).