How easy we forget our basics.

[fairybasslet]

The reason I think this concept is really cool is because I did get into a low air situation while diving the Caribsea in NC. The problem started before the dive when I was trying to fix a blown O-ring and lost 600 psi of air on an AL80. So I started the dive with only 2400 psi. Average depth was 80 fsw and it was one of the most awesome dives I've ever been on. Dozens of sand tigers all around me, some swimming about 2 feet away. The last time I looked at my gauge, I had about 1900 psi. Then, in what seemed like 2 minutes later (though it really wasn't LOL) I had 600 psi!!! Did a beeline back to the anchor line. I probably I ascended a little too quicky (at least my computer thought so), but wound up doing a 4 minute SS, during which I sucked the reg dry. It was no big deal as far as air was concerned because the ladder was right there, but I did get a little panicky about DCS. It was a good learning experience for me because I did get way wrapped up in the sharks and lost track of time. And I should have been more vigilant because I started with only 2400 psi. So if I had been aware of the estimating game, when I saw 1900 psi, I probably should have been surprised by how low I was, if I had been guestimating on the assumption that I had started with a full tank. As it was, I didn't have a proper frame of reference for the 1900 psi.

 

[DandyDon]

Fairy, why didn't you borrow air from your buddy - or someone? I hate to ask either, but did once, and I will again...

 

[fairybasslet]

Fairy, why didn't you borrow air from your buddy - or someone? I hate to ask either, but did once, and I will again...

I signaled to my buddy (actually we were diving 3 together) 6 fingers, but neglected to point to my pressure gauge first. The leader assumed I meant 6 minutes until deco and nodded and swam away. Rather than burn up gas going after her, I signaled to the other that I was going up. Seemed simplier since I wasn't OOA yet. I don't remember anyone on the anchor line, and if there were, they were doing a stop at half depth.

 

[DandyDon]

I signaled to my buddy (actually we were diving 3 together) 6 fingers, but neglected to point to my pressure gauge first. The leader assumed I meant 6 minutes until deco and nodded and swam away. Rather than burn up gas going after her, I signaled to the other that I was going up. Seemed simplier since I wasn't OOA yet. I don't remember anyone on the anchor line, and if there were, they were doing a stop at half depth.

I see - we all learn here, or so we hope. You've always seemed like a very good thinker here, and it's certainly not my place to preach to you - so here's what I try to convey to my buddies.

1 - PLEASE stay close to me, I'll try to do the same in spite of my distracting camera.

2 - PLEASE let me know when you're at 1500# & 1000#, I'll try to do the same.

> > I have those written on my slate with indelible marker to try to help to remind me to discuss this on the boat, or - if I forget, to show under water. I'm finally getting better about discussing these details on the boat, at the risk of boring buddies with same old same old. I also like particular hand signals for air, i.e. (a) hand across inside of elbow for 1500# (half tank), (b) point at spg, one finger on bicep for 1000# followed by one finger up for each hundred for specific amounts.

3 - If you're low in air, please pound chest with fist like we were taught in basic.

4 - If you're really low on air, slide your open hand across your throat like we were taught in basic as you approach me, but if you're close enough to grab - grab the yellow reg (or my pony reg - always turned on; I object to forfeiting the Manta reg in my mouth) and use it. I'll understand.

5 - I like to descend and ascend together. I'm not really tight about that, but it is best; let's try.

Threesome buddy teams are bad, bad, bad. If I have to be in one, I'd prefer to be with the DM/guide if possible.

 

[Charlie99]

A BASIC skill that I used to teach was to never CHECK your air pressure. Each time you consider reaching for the guage, stop for a moment and think what the pressure should be.

I apply the same method to my entire gauge console. Not only should the SPG reading be pretty close to what I expect, but the depth, time, and N2 loading bargraph on my computer had better be as expected.

The next step it to extend SPG forecasting to your buddy. Even with an insta-buddy, after an initial SPG comparison before splash-in, and another one after 1/4 or 1/3 tank is consumed, I usually have a pretty good feel for what a buddy has for air.

 

[Charlie99]

I also like particular hand signals for air, i.e. (a) hand across inside of elbow for 1500# (half tank), (b) point at spg, one finger on bicep for 1000# followed by one finger up for each hundred for specific amounts.

I've never seen these signals used. I've seen all sorts of varieties, but not that one.

I prefer simplicity and clarity. The "Maui method" of 1 finger per hundred psi, shown using just one hand with repeated groups of 5 at the start, is pretty clear and obvious even though a bit clumsy.

Of course, looking at a buddies SPG is even more unambiguous.

 

[DandyDon]

I've never seen these signals used. I've seen all sorts of varieties, but not that one.

I've learned a lot from you - try this. It wasn't my idea, tho. Forget who I stole it from but it is very clear.

I prefer simplicity and clarity. The "Maui method" of 1 finger per hundred psi, shown using just one hand with repeated groups of 5 at the start, is pretty clear and obvious even though a bit clumsy.

I hate that one, as flashing 5, 10, 15, 20 - takes too long and leads to miscounts. Besides, I like fingers without a spg point to be stop minutes left.

Of course, looking at a buddies SPG is even more unambiguous.

Yeah, if you stay that close. Then we bump into each other too much. Speaking from my experiences <300 dives, tho. :14:

 

[Scuba_Steve]

I > > I have those written on my slate with indelible marker to try to help to remind me to discuss this on the boat, or - if I forget, to show under water. I'm finally getting better about discussing these details on the boat, at the risk of boring buddies with same old same old. I also like particular hand signals for air, i.e. (a) hand across inside of elbow for 1500# (half tank), (b) point at spg, one finger on bicep for 1000# followed by one finger up for each hundred for specific amounts.

Holy hand-signs, WTH?

One handed, one or two numbers as required, done.

Ask any caver or any numb-nutt that's read a diving hand sign book. (IE NSS-CDS Cave Manual). It's universal, and I teach my OW students this.

Don't ever start flashing me a series "baseball pitch" signs or I'll thumb the dive on you cause you're pi$$in' me off lol

Holy crap already gents. Keep it simple, standard and universal. It's been done already, don't re-invent the wheel.

 

[dumpsterDiver]

Then, in what seemed like 2 minutes later (though it really wasn't LOL) I had 600 psi!!! Did a beeline back to the anchor line. I probably I ascended a little too quicky (at least my computer thought so), but wound up doing a 4 minute SS, during which I sucked the reg dry. It was no big deal as far as air was concerned because the ladder was right there, but I did get a little panicky about DCS.

Glad you made it up without a problem. Doing an exciting dive in "different conditions" (i.e., lower tank volume) is exactly the situation where you tend to loose situational awarness. However, for a no-deco dive, leaving the bottom with 500-600 lbs in an 80 should not really be a problem, if you are not working against a current or having a problem or are out of breath.

In a situation like you described, I would recommend that the diver strive to do a slow ascent. Maybe come up the first 20 feet kinda fast (like 60 feet per minute) and then really slow down and carefully watch the air. My personal belief is that you would be better off doing a slow and relaxed ascent and then blowing off the safety stop rather than violating your computer's ascent rate alarm while you try to hurry toward the surface and do your safety stop at 15 or 20 feet. Clearly, if you had air left over after the slow ascent, you should also do a safety stop, but rushing up to complete deco (or a safety stop) is very risky.

 

[DandyDon]

Holy crap already gents. Keep it simple, standard and universal. It's been done already, don't re-invent the wheel.

Care to explain...?