novice questions about emergency air

[syruss32]

Wow this thread has a lot of good information. I may have to eventually get me a pony. But I think the reality is that often having items like this is just overkill.

While taking my OW class I actually ready the book and many places it mentions to check your air regularly. During the water sessions that was never brought up. Even when on out checkout dives that were only like 20-25 minutes it was not mentioned.

I got in the habit of checking every couple minutes and I think that is a good habit to learn early. I have not dove with very many divers (5-6 so far) but I seem many tendencies towards unsafe diving.

I was diving a couple of weeks ago and there were 3 of us (unfortunately we had to dive short a buddy since he didn't show up and we were in a shallow lake 56 feet so it was fairly safe.) The person who was leading has quite a few dives and is VERY safety oriented. He checked out both of our gears, as I checked theirs, the other guy didn't check anything. Then in the course of diving we were in visibility in the 2-3 foot range, so we had to stay close and use lights. The leader kept checking to make sure we were okay on air, I was about 800 when he last checked and signaled to surfact. The other guy signaled he was okay too. So at the safety stop we were hanging out for 3 minutes and up we went. When we got to the surface we all wanted to check air. Me mostly to see how I am doing in comparison to other divers, I was at 500 on the money. The leader was at 1400 (I know he is half fish now) and the third guy was at 200 or so. That is unsafe. Had we been deeper and needed a longer stop or something happened he would have be surfacing empty.

So I think from this I learned how important it is to check and re-check. Always leave a cushion. I want to know that 500 psi is a cushion that is ONLY to be used in an emergency, not just because I can. The third guy should have said he was low on air earlier and surfaced with a full 500 in my opinion.

So I doubt I will go buy a spair air or a pony any time soon, but I am going to make a conscience effort to make sure to check air regularly and also to make sure to do my safety stops and still be at 500 when done.

I think instructors should really harp on this to new students as it could save their life. Maybe make it so if he asks you how much air you have and you signal (without looking) making a best guess. If it is within a couple hundred PSI (a few minutes worth showing you must have checked fairly recently) all is well, if not you owe the instructor a beer.

I owed my instructor a 6 pack for standing my gear up and being more than 3 feet from it.

So there are my 2 cents and 534 words on the subject of safety and air.

 

[WetDane]

Ok, so as far as the Spare Air thingies goes - if you dive to no more than 20 fsw and feel that is your limit - go ahead...
If you plan to actually dive recreationally and MUST have a spare air setup - get a pony - 19 cuft - learn how to use it.

IF you really want to dive - consider this scenario:
When I dive with my crew - we usually have an air share drill, a valve drill and a mask off drill before the dive commences - we have many dives that are only to to drill specifics such as buoyancy and trim as well as streamlining... This is where you learn what your buddy knows and what he dives. You will often see simulated OOA drills on rec dives around 100 fsw when I go diving.
This will take you a long way towards good diving practises and eventually you will end up with doubles and a whole new thought about this issue.
(If you want to know more about this - drop me an email and I will give you some pointers).

I know some people will think this is beyond the point of recreational diving - but really - don't you want to be the best diver you can? It is not just an issue of you being safe with your buddy, but also of your buddy being safe with you - are you prepared?

It sounds to me like you were taking a regular OW class and the instructor turned off your gas?! I would not stop by putting my foot in his ass...

Anyway - my opinion - since you are a new diver - is: Save your money for now - spend the $300 on going diving! It is too soon for you to make an educated decision and if your LDS is anything like some of the ones around here - they are more than happy to sell you another gadget (btw - if they sell the spare air - they do not qualify as a LDS - but rather as a profiteering outfit).

Now - go back and read LY's instructions one more time - then go diving 20 times and then think about it again.

LD -
I think you are aking about the rule of thirds? turn around when you have used one third of your gas - I believe the theory goes something like this:
You use 1/3 going out - you turn when you have 2/3 left - this way you need 1/3 to get back up and in case of a problem you still have 1/3 to spare for your buddy - you can now deal with all safety issues as needed.

Cheers,
Big T

 

[jackdav]

The OOA simulation was not completely unexpected..... the class was doing the drill.... my instructor just caught me unaware by not going down the line in order ..... he skipped over two other students to come in behind me and close my valve..... which I thought was good... if I KNEW in advance that I was going to run short on air on a dive, I would never go near the water. Also, the instructor was right there the whole time keeping an eye on me and ready to pull me to the surface if need be. My buddy and I both learned important lessons during the exercise, and all that happened negatively was a bit of very survival-valuble fear and panic (which I now know IN MY BONES should be avoided). So I really have to stick up for my instructor .... if anyone is to blame it's me for not keeping a closer eye on him.
Really stoked by the amazing quality of people and opinions on this List,
Jack

 

[WetDane]

Good point Jack,

If you knew it is a whole different story...

You will get a lot of info from this board - there are a lot of people who knows a lot about diving - If I have any solid advise you shoudl take - it is to do 20 dives before you buy something - you will not believe the way your opinion about something can change in 20 dives...

Good luck and welcome,
Big T

 

[large_diver]

Dane,

I wasn't specifically referring to the rule of thirds, I was just asking what typical diving practice is for most folks. If a buddy pair is surfacing from deep dives with 500PSI or less, they probably need to re-evaluate their gas management techniques. I agree pony is not the answer to this issue.

I think I have my own situation in mind here, since I am large and consume gas faster than the average human. If we are at 100 feet and my smaller buddy is diving an AL 80 with the intention of surfacing with 500PSI.....would this be enough to get both of us to the surface....? I would say no.

-LD

 

[WetDane]

Hm, I see where you are going with that LD.
In my experience this clearly become a part of planning your dive and diving the plan.
I agreed that if you ascent from depth with 500 psi left your are never going to get both of you up safely.

I would say that when you are planning the dive you need to take into account emergency bailout options - such as surfacing away from the entry point - you also need to know what the current then could potentially do to you if that happens. You need to know what your scenario is to surface with a controlled ascent - AND you need to know if you can manage a controlled ascent only by looking at your depth gauge and not having a line?
Obviously this planning becomes more serious when you are doing a deep dive compared to doing a rec 60 - 80' dive (ok, that all depends on your experience).

This also leads into diving with the same buddies all the time - I dive with a small group of a dozen or so people, we all know how the others behave, what the skill level is and what to expect.

Another thing is location - warm and clear water is a lot easier than my backyard (cold and murky - we think 15' viz is a great thing...)

Big T

 

[Rick Murchison]

It is interesting how times, attitudes and procedures change. When I took my first diving course, we had no SPG's (the wimps had "J" valves, but us really manly men had "K" valves - "when it gets hard to breathe, it's time to head for the surface"), no BC's and no wetsuits (in the Sunny South, don'tchaknow) and for most of us no weights needed either (young hardbodies diving steel 72's)...
Our instructor surreptitiously turned off the air at least once on every dive. We were expected to check the valve open while moving to buddy breathe (oh, yeah, no safe seconds in those days either). I think this was pretty standard practice at the time.
I see many new divers positioning their tanks where they cannot possibly reach the tank valve - and at least once a year I read an accident report where someone has had a mishap because they either jumped in with the air off or with the valve just a quarter turn open, and either couldn't or didn't just reach back and turn on the air. I personally think valve manipulation under water should be reintroduced into open water courses as a mandatory skill.
Rick

 

[WetDane]

Hehe -
Nice try Rick -

- I actually second you on that one, in class I recall learnign to take the BC OFF to manage stuff - I imagine the valve as well - now a days my diving philosophy is that the only way that rig comes of me is if you pry it from my cold dead fingers - alas - I have to figure out how to manage the valves with it on.

Another thoght for Jack though is:
If you are in Arizona (if I recall correctly this is primarily a desert) - will you be going places to dive - and if so - can you take that pony on the plane?

Big T

 

[jackdav]

..... good point about taking the pony on the plane .... I hadn't thought of it. I heard that you can transfer cyllinders via air if you remove the stem from them ... although this seems like a lot of trouble.... mostly, though our diving will involve driving to San Diego (5 hours) or Mexico (7+ hours). I have a brother who lives in Beliz and getting the tank down there might be quite a hassle...... is this difficulty really insurmountable?
Best Regards,
Jack

 

[Rick Murchison]

Unless regs have changed since 11 Sep, Airline/FAA regs let you check high pressure tanks with 50psi in 'em.
Customs, however, is a different matter - those folks frequently want to look *inside* the tank to make sure there are no drugs there (nowadays they'd probably want to look inside for explosives, too - I would).
So, to avoid hassles, drain the tank and remove the valve yourself - your LDS should have a packing plug you can use to keep stuff out of the tank while the valve is off. A 30 will fit in a suitcase fine with the valve removed.
Rick