How those idiots (us) run out of air

[uncfnp]

I can actually see where this is all coming from.

If divers only went on dives they're qualified to do without a "guide", some island economies would collapse. Bad for the SCUBA industry. Bad for tourism.

The entire industry is based on "follow me and you'll be OK".

This works great until it doesn't.

It's really unfortunate that OW class doesn't have more "Oh Shi*!" requirements that drive home exactly what the risks are underwater. A book chapter and test questions that cover things like "what to do when you're low on air" would be great too.

flots.

If a real life "Oh Shi*!" moment and 100 SB posts hasn't driven it home, I don't know that any class would and certainly not a book.

 

[RJP]

BTW I totally agree that the agencies DO NOT teach good buddy diving and I fault them for that. They talk about it but do not teach it.

Agencies don't teach ANYTHING. Instructors do.

 

[spectrum]

?
I just use what the military taught me: 1-5 =fingers are shown vertical, 6-9 =fingers are shown horizontal. Forget the last two numbers of your PSI, its immaterial (ie everything is assumed in 100's). Just do the first two numbers. Zero is the standard O with the hand. Unless you're a Buckeye, then you know how the O should be done!

There have been a slew of threads over the years describing the many pressure singaling protocols, some bordering on chisenbop. Based on the methods divers have been presented to me with over the years the only useful method is the one agreed on prior to the dive. For that to work it needs to be wicked simple.

Put me down for 1 fist pump per 500 followed by 1,2,3 or 4 additional fingers as needed.

Pete

---------- Post added July 2nd, 2013 at 10:25 PM ----------

To the OP...

My goodness you were there with a buddy and you put yourself at risk to let a DM do what? Game over, go up safely with your buddy.

 

[tracydr]

I will reiterate what I have said in other threads before. We learn how to use a compass in OW training. But, we don't learn how to use it very well. If you can't do an out and back reciprocal, you must practice this each and every dive.
I take a heading every dive with my compass because its a skill I need more practice on. It's a very important, vital skill.

 

[billt4sf]

I slept on it and I am beginning to come around. See what y'all think.

I agree that it was a mistake to think that "I don't have enough air to do what the DM wants but I am going to stick with her". I did think that at some point. Stupid me.

At 50' stressed, when to start for the surface? -- when we know we have enough air to make a it safely, with some reserve. Maybe 500 lbs? I can do an unstressed ascent from 50' next to the line with abt 300 lbs incl. a safety stop -- unstressed. So 500 sounds maybe about right.

Assuming that we had done this, she probably would have noticed us and followed. Actually by the time I was at 500, we were together with her, heading for the mooring line. She should have led us up at an angle, at a minimum at that point. I will mention that to her.

Here's the kicker -- you'll love this. She is a DM in training, with 80 dives. We have about 60. Note to self -- find out the training level and number of dives of everyone I dive with BEFORE starting out.

Am I making progress?

Bill

 

[doctormike]

I slept on it and I am beginning to come around. See what y'all think.

I agree that it was a mistake to think that "I don't have enough air to do what the DM wants but I am going to stick with her". I did think that at some point. Stupid me.

At 50' stressed, when to start for the surface? -- when we know we have enough air to make a it safely, with some reserve. Maybe 500 lbs? I can do an unstressed ascent from 50' next to the line with abt 300 lbs incl. a safety stop -- unstressed. So 500 sounds maybe about right.

Assuming that we had done this, she probably would have noticed us and followed. Actually by the time I was at 500, we were together with her, heading for the mooring line. She should have led us up at an angle, at a minimum at that point. I will mention that to her.

Here's the kicker -- you'll love this. She is a DM in training, with 80 dives. We have about 60. Note to self -- find out the training level and number of dives of everyone I dive with BEFORE starting out.

Am I making progress?

Bill

NOW you're thinking like a diver..!!

Your rock bottom ascent pressure in a non-overhead, non-deco situation would depend on a number of factors (depth, SAC rate, etc..). Also, as was mentioned, sometimes at low pressures the SPG is not always accurate. So that number is going to vary, but even at a conservative ascent rate of 30 FPM (PADI says 60 FPM maximum) you should be at the surface in less than two minutes from 50 feet if you omit the safety stop - which you could do if there was a risk of going completely OOA. Also, remember at 15 feet you are using gas much less rapidly due to the lower ambient pressure and the lessening in panic that happens near the surface, so it would be rare to actually have to blow off the safety.

Good thing that you didn't tell us before that your dive planning involved the gas on the back of a DM candidate with 80 dives... we would have REALLY given you a hard time! But I think that our advice stands, even if you were diving with John Chatterton or Jacques Cousteau...

 

[Imla]

I am sorry if I am very blunt now... (It may be a scandinavian thing... )

Will you seriously tell us that

1. You have 60 (!) dives, and STILL not learnt basic life-supporting skills as GAS-management, navigation and free ascents?

2. WHO CARES if she (I assume you meant the DM) follows. When you reach the agreed upon turnpressure for your buddyteam, you follow your plan. Wave goodbye and smile!

3. I am assuming that you mean that "she" (The DM in training) was the guide? Do you really mean to imply that this is HER fault?

COME ON!! Either get a grip in reality, or stop diving! If you by 60! dives still cannot manage gas, ascent, navigation or stress in a better way, and that these basic skills are so poor that you actually end up in a life-threatening situation because of it, then maybe you should a) pay for a private guide b) get more training c) both or d) Nope.. I would never say quit.. but come on..

 

[Tortuga68]

Imla, you're not saying anything that hasn't already been said in this thread. Post #107 is a little late for histrionics

Am I making progress?

Yes

At 50' stressed, when to start for the surface? -- when we know we have enough air to make a it safely, with some reserve. Maybe 500 lbs? I can do an unstressed ascent from 50' next to the line with abt 300 lbs incl. a safety stop -- unstressed. So 500 sounds maybe about right

http://www.scubaboard.com/forums/basic-scuba-discussions/90264-rock-bottom-spreadsheet.html

 

[Lorenzoid]

Speaking of rock bottom, my wife and I started experimenting with this concept on some recent dives in the Keys (Spiegel Grove, etc.) to see how it would work out in practice. What sadly became clear to us is that, under strict rock bottom planning principles, we do not take enough gas for many of the dives we do. (What, none of you are surprised?) I'm sure this has been discussed ad nauseam in other threads, so I don't mean to divert this one. But many of the dive ops we use don't even offer 100 cf tanks as an option, and when we used the ubiquitous AL 80 like every other diver on the boat, we found the rock bottom number indicating us to ascend to a shallower depth at just about the time everyone else is halfway through poking around the deck of the wreck (maybe only slight exaggeration here). I can just picture a DM reacting to our request for 100 cf tanks to dive a wreck in 90 feet of tropical water: "You crazy, mon?--you don't need that and we don't have that." I also understand that whether rock bottom or rule-of-thirds or still some other alternative is the more appropriate way to plan a dive may depend on the dive profile.

Again, no intent to divert the thread here, but when I saw rock bottom brought up, it piqued my interest because we have been delving into this concept. In many ways, my wife and I are still inexperienced divers. Only after 200+ dives is "gas planning" becoming part of my vocabulary. It's good that Bill is getting the lesson early on.

 

[captain]

I slept on it and I am beginning to come around. See what y'all think.

I agree that it was a mistake to think that "I don't have enough air to do what the DM wants but I am going to stick with her". I did think that at some point. Stupid me.

At 50' stressed, when to start for the surface? -- when we know we have enough air to make a it safely, with some reserve. Maybe 500 lbs? I can do an unstressed ascent from 50' next to the line with abt 300 lbs incl. a safety stop -- unstressed. So 500 sounds maybe about right.

Assuming that we had done this, she probably would have noticed us and followed. Actually by the time I was at 500, we were together with her, heading for the mooring line. She should have led us up at an angle, at a minimum at that point. I will mention that to her.

Here's the kicker -- you'll love this. She is a DM in training, with 80 dives. We have about 60. Note to self -- find out the training level and number of dives of everyone I dive with BEFORE starting out.

Am I making progress?

Bill

I have done accents from 80' starting at 200 PSI. It is not difficult. Back in the day when J valves were all we had you began just about every accent at 300 PSI. That was the pressure the J valve held in reserve. In 55 years of diving, the first 10 years without an SPG I have never run out of air. Out of air means you can not get another breath out of the tank, 500, 300 even 100 PSI is not out of air.
You and you alone are responsible for not running out of air and getting yourself to the surface before you do.