refusing an instabuddy

[TSandM]

This makes little sense. If you and your buddy are smart, you are back to the surface with 500 lbs left in your tank. Even if you are at 100ft and have to share air, 500 lbs should be enough to get you and your buddy back to the surface.

I'm sorry, but this is quite wrong -- wrong enough that I had to respond to it.

The calculations are rather simple. If you assume that a) the divers have the average gas consumption of an adult male, at about .7 cubic feet per minute, and b) they are diving the ubiquitous Aluminum 80 tank, here's what you come up with: You are at 100 feet and someone runs out of gas. He signals, you establish an air-share, and decide to abort the dive. Let's say that takes a minute (and you may think that's way too much time, but having participated in many classes where out of air situations are thrown at students, it takes at least that long, and people are quite surprised by it). Let's also say that both divers are somewhat stressed by the novel situation, and have increased their gas consumption by a modest 50%, to 1 cfm. (In actual emergencies, it can go much higher.). You have now used 8 cubic feet of gas between the two of you.

Now, let's consider an ascent at the currently recommended maximal rate of 30 fpm. It will take you 3 1/2 minutes to get to the surface, and your average depth during the ascent is 50 feet, or 2.5 ATA. At 2.5 ATA, the two of you, at 1 cfm per, will use 5 cfm per minute, or about 17 cubic feet for the ascent. Add the 8 cfm for the bottom time, and you have 25 cubic feet of gas used during a direct ascent. 25 cubic feet, in an Al80, is 1000 psi, or just about twice what you thought was adequate to deal with the emergency. And this is assuming that everything goes smoothly and the ascent is continuous and at the appropriate speed, and also that both divers are capable of managing their stress and keeping their gas consumption close to what they normally use.

The fact is that OOG emergencies require a good deal more gas to manage than most people realize, even assuming that you handle them neatly and that you (probably properly) ascent at the maximal rate and omit any safety stops. Maintaining minimum gas reserves is IMPORTANT, and should be part of the pre-dive discussion with instabuddies.

 

[SparticleBrane]

To add to what TSandM has so nicely spelled out -- there's a good chance that if you are in an OOA situation, either you or the other diver might be huffing and puffing from the surprise and stress. You might just suck down that gas you left in reserve much faster than you'd expect...and then you've got a real problem if both of you are OOA. Gas management is pretty important.

 

[Peter Guy]

Just to add a couple of comments:

a. Depending on WHERE you are diving, as a buddy you may well have a legal liability -- that of being a good buddy. For the person who wrote there is no liability, please provide your basis for that claim.

b. I've not had too many insta-buddies, primarily because I generally do my dive traveling with my diver wife -- but I have had a few. I hope they thought they had a good insta-buddy! My last pairing was, in fact, a lot of fun as I was paired with a new diver who I ended up coaching through her portion of the dive. When she, and her husband who was paired with the DM, got low on air, they buddies up and went to the boat leaving the DM and I to have a 30 minute dive to ourselves.

 

[mathauck0814]

The fact is that OOG emergencies require a good deal more gas to manage than most people realize, even assuming that you handle them neatly and that you (probably properly) ascent at the maximal rate and omit any safety stops. Maintaining minimum gas reserves is IMPORTANT, and should be part of the pre-dive discussion with instabuddies.

Perhaps an anecdote can help to underscore this. I was showing a visitor to the area around our local wreck the HMCS Yukon. a 366-foot long destroyer escort lying on its port side in about ~95 feet of water (+/- depending on tide and where you are along the bottom). The diver was from the Pacific Northwest, was accustomed to "real" cold water diving (his words) and came armed with all the gear you'd expect to see a reasonably experienced cold water diver in (dry suit, hood, gloves, etc).

We descended along the mooring line nearest the forward guns and got out in front of the bow with terrific visibility - I wanted to show him a front on look at the wreck. We are at ~90 feet, about 8 minutes into the dive (approaching the halfway/turn point as we'd planned 20 minutes to the bow and back to the forward guns). I turn to signal to him to look at the wreck and I see him pull off his reg 3 times and not exhale. He'd managed to suck his tank dry in 8 minutes. Not low on air - out of air. I deployed the long hose on my bail out (I am closed circuit, so he cannot receive directly the gas I am breathing) an AL40 with EAN32 with a standard stage kit. He didn't fight me in receiving the regulator and I pushed him quite briskly to the nearest upline (on the bow) and up to the surface. I maintained our ascent speed but opted out of the safety stop as he was plowing through gas and I wanted out of the water.

We arrived at the surface and I had to orally inflate his wing - his tank was THAT empty. The swim to the upline and the ascent had taken 5 minutes. He informed me that he was unaware that he'd emptied his tank, admitted to having been "freaked out" under water in the moments leading up to my giving him my bailout tank.

So in the 8 minutes we'd been in the water, the ~1-2 minutes it took us to get the donation sorted and the 5 minutes to ascend (15 minutes total dive time to a max of 95 feet, call it an average of 60 feet) he'd sucked his AL80 and my AL40 dry. Keep in mind that on the ascent I was still on my loop and not sharing his gas, so he had access to all 40ft^3.

120ft^3 in 15 minutes from an "experienced" cold water diver who had a panicky episode.

Still think 500psi is enough to get you home safe?

 

[boulderjohn]

I was just reminded of an interesting insta-buddy case. When I signed up for the dive, it was the shop owner, whom I had met before, who did all the paperwork. We had a pleasant chat about diving. I then went to the boat location and got on board. It was the DM's job to identify buddies, and when he found I was the only single diver on the boat, he turned to the pair next to me and asked if I could join them. The guy he asked growled, "I don't know--does he have any idea what he's doing?" The DM said, "I don't know." He turned to me and said, "Do you have any idea what you're doing?" Not feeling the warmth of that welcome, I just said, "I have an idea." That was good enough for the DM, although the other two were clearly not happy. I watched them set up their gear quietly for a minute or two, but when I saw they were having trouble, I politely stepped in and helped them with the mistakes they were making. They were not very appreciative. They did not even say thanks as they made the changes I showed them.

A couple minutes later the owner and his buddy arrived on the boat to check things out. He came over and chatted with me briefly, then asked me who I was diving with. I pointed to the pair next to me, ad his eyes got wide. He turned, walked over to another group, talked to them briefly, and then came back to me. He told me I should dive with the other group. I went over to talk to them. They greeted me warmly, and we had a great pair of dives together. The other two? Well, let's just say their very, very brief dives went as they liked it, without the horror of having me along with them.

The key factor in that case was a really bad job by the DM. He made no attempt to identify my level of training and experience before assigning me to the least trained and experienced people on the boat. He further did it in such a way that it made it impossible for me to do anything about it without coming off as a jerk. I would not have dreamed of coming across with the air of smug superiority they had shown to me. I don't think I have ever had another experience like it.

 

[tursiops]

My wife and I are both instructors. We were on a dive boat out of the Keys and the DM in charge asked if everybody had a buddy. One guy far on the other end of the boat raised his hand and said he did not. The DM asked if that guy could buddy with anybody; I looked at my wife and she nodded OK, so I said, "Sure, us." Well, a lot happened in a short amount of time and we never really got a chance to talk to our new buddy, and we all got in the water and dropped down together. I swam over to him and gave him an OK sign; he responded with two thumbs up. I gave him another OK sign, and he looked at me for a moment, nodded his head, and gave me an OK back. I took a good look at him: no alternate, no time piece, just a console with an SPG and a depth gauge. I kept really close to him during the dive, kept watching his SPG, and cut the dive short because I had no idea of his nitrogen status, although it was the first dive of the day. His gas was dropping down anyway. The three of us surfaced, and I asked him if he always dived without a watch or computer or alternate, he said yes, he didn't need those things, because he always dove with people more experienced and stayed shallower than them.

The next day, same boat, same DM, same scenario...a different guy needed a buddy. I looked at my wife and her eyes did a 360 while she was shaking her head no. The DM got no offers to take the guy on, so told us the boat was not leaving the dock until the guy had a buddy. Still no takers. So I go over to the DM and said maybe we'd take him, but I wanted to talk to him first. Be my guest, he said. As I'm walking over to the guy the guy gets a big smile on his face and says, "I'll bet you are an instructor. PADI?" I said yes. He said, "Well, I'm one of PADI's lawyers, just out for a fun dive, and I'd be delighted to go with you guys. OK?" Off the three of us went, on a terrific dive; the guy showed us stuff we would not have seen by ourselves, and was a perfect buddy.

So, you never know what you are going to get, but it is a good idea to check it out before getting to the bottom!

 

[ev780]

Hi. My name is EV780 and I am an insta-buddy. I have been an insta-buddy for 22 years.

{Hi ev780!}


Confessions of an insta-buddy.

I am a good diver but a terrible buddy. Same ocean same day anyone? I abhor the buddy system and all it stands for because even in the best situation it is a marginal safety system at best. I realize that caving and deep wreck penetrations have different rules. Just not my thing. The solo movement in certain agencies that promotes redundancy and proper prior planning is a welcome change IMHO! In a group dive we are all in this together so, shouldn't we be everyone else's source of assistance? I know in my safety planning, which is usually an OOA situation, I always envision getting to the closest source of air whether it is the canned variety or the unlimited one. The reinforcement of the buddy system ingrains a subconscious thought into a diver that their only source of help is their buddy. They forget they may be only 50 feet away from real air and swim 200 feet to get to their buddy. I have spent a lifetime in emergency situations and a person without a lot of experience in these things, we will fall back on what is learned first. This continual harping on the buddy system is a huge mistake because it will be what a diver defaults to unless they have a lot of experience dealing with adrenaline dumping.

Anyway, on to confessions. Some are tongue in cheek, some are not. You can decide.

* "Oh please dear boat crew, don't pair me with the guy that has the alert horn or the tank banger."
* Same with snorkels.
* Same if all of their gear is from the same manufacturer. My personal best red flag.
* I lose all interest in my new insta-buddy when they want to do the BWRAF check.
* Old gear. Awesome, I want that diver.
* If they are hyper on the deck they will be hyper underwater.
* I never get the good looking one. (I am certain they say that about me too.)
* If they confess to being a new diver. Not usually a bad experience.
* If in the first five minutes I get their dive resume, usually a bad experience.
* My only truly bad experience was when some lady looked down her nose at me because I only had 200 dives. She ended up blowing a lung at 70 feet and had to be evacuated.
* One of my best experiences. During briefing DM paired my up with a guy who just looked the part. As men do, we threw each other the chin lift head nod thing. Subtly checked each other's gear and went diving. Not sure we ever spoke a word to each other.
* 90% of them have been just fine. Normal people, divers who love to dive. Just don't have any diving friends.
* Cruise ship diver. "Danger, Will Robinson!!!!"
* Tattooed divers are good divers.
* Tip the crew hard early in the trip and you will get a better insta-buddy.
* Watch out when you are the third wheel with a couple. Especially if they are newly in a relationship. Someone is usually trying to impress someone else and you will be resented if you have any skill at all.
* Beware of dive operations who take this stuff too seriously. Usually means a nanny state.
* There is no substitute for personal responsibility.

That's enough. Seriously though, almost all of them have been just fine.

 

[azmodan50]

If that is saving you enough air to make a significant difference in your dive time, you are either doing a very unusual dive or you need some work on buoyancy skills.

First, if you are properly weighted, it will take very little air in your BCD to be neutrally weighted. Your BCD should be barely inflated during a dive if you are properly weighted.

Let's next consider a dive with a square profile. Once you hit your depth and add the correct amount of air in the BCD, you should theoretically not have to add any more air for the rest of the dive. Your changes in buoyancy with your minor depth changes should be accomplished by your lungs. Now let's look at a multi-level dive. You should be starting at your deepest point and then moving progressively shallower, so the only changes to the BCD should be removing expanding air, not adding more air. It is true that you will probably not follow the square and multi-level profiles perfectly, but extra descents should not happen often for most divers.

Finally, let's look at a dive in which you are going over terrain with varying contours and thus varying depths. In that case, you may have more than one descent that requires adding air. For most divers on most dives, that won't happen a whole lot. I once did a cave dive in Mexico where I was indeed going up and down a whole lot. My computer profile looked like an EKG printout. In that case I was using my inflator more than I would like, but that was very unusual, and it is not something the average diver will encounter.

If you are overweighted and diving shallow, you may have more of a problem. Every pound of excess lead requires nearly a pint of air in the BCD to compensate. The more shallow your dive, the more that excess air will react to minor changes in depth. The more air that is expanding and contracting with those changes in the BCD, the less your lungs will be able to overcome those changes. In that case, the better solution is to cut back on the excess lead.

Did you read his post? Did you read all of mine? He said he had bouyancy issues and I said that it won't save you a ton of air.

 

[boulderjohn]

Did you read his post? Did you read all of mine? He said he had bouyancy issues and I said that it won't save you a ton of air.

You said, "It won't get you a ton of extra bottom time though."

I think I just clarified that after your explanation of how to save air and get more bottom time that way, your statement that "it won't get you a ton" = "it won't get you barely any at all." My comments went on further to point out that if it is getting you a lot more bottom time, then you should look at other reasons for the problem, and it suggests those reasons.

Is there something wrong with what I said?

 

[azmodan50]

Perhaps an anecdote can help to underscore this. I was showing a visitor to the area around our local wreck the HMCS Yukon. a 366-foot long destroyer escort lying on its port side in about ~95 feet of water (+/- depending on tide and where you are along the bottom). The diver was from the Pacific Northwest, was accustomed to "real" cold water diving (his words) and came armed with all the gear you'd expect to see a reasonably experienced cold water diver in (dry suit, hood, gloves, etc).

We descended along the mooring line nearest the forward guns and got out in front of the bow with terrific visibility - I wanted to show him a front on look at the wreck. We are at ~90 feet, about 8 minutes into the dive (approaching the halfway/turn point as we'd planned 20 minutes to the bow and back to the forward guns). I turn to signal to him to look at the wreck and I see him pull off his reg 3 times and not exhale. He'd managed to suck his tank dry in 8 minutes. Not low on air - out of air. I deployed the long hose on my bail out (I am closed circuit, so he cannot receive directly the gas I am breathing) an AL40 with EAN32 with a standard stage kit. He didn't fight me in receiving the regulator and I pushed him quite briskly to the nearest upline (on the bow) and up to the surface. I maintained our ascent speed but opted out of the safety stop as he was plowing through gas and I wanted out of the water.

We arrived at the surface and I had to orally inflate his wing - his tank was THAT empty. The swim to the upline and the ascent had taken 5 minutes. He informed me that he was unaware that he'd emptied his tank, admitted to having been "freaked out" under water in the moments leading up to my giving him my bailout tank.

So in the 8 minutes we'd been in the water, the ~1-2 minutes it took us to get the donation sorted and the 5 minutes to ascend (15 minutes total dive time to a max of 95 feet, call it an average of 60 feet) he'd sucked his AL80 and my AL40 dry. Keep in mind that on the ascent I was still on my loop and not sharing his gas, so he had access to all 40ft^3.

120ft^3 in 15 minutes from an "experienced" cold water diver who had a panicky episode.

Still think 500psi is enough to get you home safe?

Well I'm sure that if I took an LP108 to 20ft and paid absolutely no attention to my air and stayed down way too long, I may not have enough air to surface.

You guys are missing the point. No matter what you do, you can't plan for stupid. My post was in relation to a statement that if you increase your tank size so your bottom time matches your buddy, it may not be a good thing because your buddy has a smaller tank.

And I believe that in an emergency out of air ascent, you wouldn't stick to the 30fpm rule. And again, if you are at 100ft with 500 lbs of air, that's just stupid. Even if one person goes out of air, the other should have plenty to make a direct ascent for both divers.

As far as the anecdote, shouldn't your buddy have been prepared as if a solo diver considering that you would not be much help in an OOA situation? Where was his pony bottle?

We are talking about the average situation here, not the extreme worst. First, you should be paying close attention to your air. Second, you shouldn't be at depth with only 500 lbs of air. And third, in such a situation, 500 lbs is more then enough. You don't have to get all the way to the surface on it, just close enough. If I were at 100ft and had no air, trust me, my weights would be off and I would get back to the surface. I would much rather spend time in a chamber then a coffin. The closer you get to the surface on that 500 lbs of air before ditching your weights may just make a little difference.

---------- Post added July 3rd, 2014 at 04:03 PM ----------

You said, "It won't get you a ton of extra bottom time though."

I think I just clarified that after your explanation of how to save air and get more bottom time that way, your statement that "it won't get you a ton" = "it won't get you barely any at all." My comments went on further to point out that if it is getting you a lot more bottom time, then you should look at other reasons for the problem, and it suggests those reasons.

Is there something wrong with what I said?

Nothing other then I never said that you would get significant time. But a person that is constantly inflating their BC might get an extra minute or two if they manually inflated. And the poster said that they had buoyancy issues.

And I never said it was a great way to conserve, but it is a way.

If anyone has better suggestions on how to conserve air that don't include things that take time and practice such as be more efficient or control your buoyancy better, help the man out. I had already suggested diving a little shallower then his buddy.