Checking your buddy's gas

[dfx]

The only total failure is a diver not monitoring their own gas supply AT ALL, and pretty much every technically-trained diver I've met is at least aware enough to know that they're working harder than expected, and check their gas more frequently as a result. If they're not aware enough to do that, there's an extremely high chance that I wasn't willing to get into the water with them on a dive in the first place.

This is exactly the scenario I was asking about. So how do you know that ahead of time? How do you know that your judgement of another diver is 100% correct? Wouldn't it me smarter/safer to still check on them, at least once?

 

[kelemvor]

Switch to a CCR and be done with it.

You buy, I'll fly!

 

[Hepcat62]

This is exactly the scenario I was asking about. So how do you know that ahead of time? How do you know that your judgement of another diver is 100% correct? Wouldn't it me smarter/safer to still check on them, at least once?

In my case, I primarily dive with people whose training I am familiar with - that addresses a large number of potential issues up front. Additionally, a pre-dive briefing is something I do and expect from everybody I dive with, and gas planning is a big part of that. How that briefing goes can be very instructive. I also don't go on dives where a potential buddy stands a significant chance of injuring me through negligence without having dove with that buddy before. You can learn a lot about a buddy on a shallow dive, and make a decision then about where you're willing to go with them in the future.

To your point, there's rarely harm in checking. For divers without technical training or - really - training in gas planning/management techniques, I would certainly recommend checking. I would ALSO strongly recommend that they seek out training in gas planning/management techniques ASAP.

IMO, most cases where cross-checking would be necessary are actually symptoms of failures that occurred before getting in the water.

 

[MaxBottomtime]

The people I dive with have better air consumption than I, so I just check my own, often.

 

[dfx]

In my case, I primarily dive with people whose training I am familiar with - that addresses a large number of potential issues up front. Additionally, a pre-dive briefing is something I do and expect from everybody I dive with, and gas planning is a big part of that. How that briefing goes can be very instructive. I also don't go on dives where a potential buddy stands a significant chance of injuring me through negligence without having dove with that buddy before. You can learn a lot about a buddy on a shallow dive, and make a decision then about where you're willing to go with them in the future.

To your point, there's rarely harm in checking. For divers without technical training or - really - training in gas planning/management techniques, I would certainly recommend checking. I would ALSO strongly recommend that they seek out training in gas planning/management techniques ASAP.

I don't think you're quite getting my point. I'm not talking about negligence. I'm talking about simple human nature. Part of human nature is to make mistakes. Everyone makes mistakes. That's the "what if" case I was referring to. What if your buddy simply screws up, despite you having full trust in their skills and their training?

 

[Hepcat62]

I don't think you're quite getting my point. I'm not talking about negligence. I'm talking about simple human nature. Part of human nature is to make mistakes. Everyone makes mistakes. That's the "what if" case I was referring to. What if your buddy simply screws up, despite you having full trust in their skills and their training?

I guess you and I have different definitions of what it means to "screw up". To me, a "screw up" is a momentary failing - a mistake. Not monitoring your gas for an extended period of time is not a screw up. It's a total lack of awareness, and is likely to be noticed in other ways well before somebody runs out of gas. Even if it does happen, I'm his backup brain. It's part of my job to be aware of how my buddy is acting. Too many large clouds of bubbles (exhalations) in too little time? Might be a good time for me to check in...

For tech divers who are well trained, even a fairly significant task/problem should not result in a total loss of awareness. There should be effectively no situations where they would experience such a loss of awareness that is not ALSO a significant enough problem that their teammate is going to be sitting in front of them observing VERY carefully.

More directly related to the question, this may be one of those things that's not clear to people who haven't sought out gas planning/management training. Even in the event of a buddy who loses all awareness and blows through their gas, I've got enough to get us both out of there safely. We planned the gas that way, or we didn't go diving.

 

[buddhasummer]

I am recreationally trained. My #1 regular buddy I rarely check as our gas consumption is almost identical, his possibly a little better than mine, we both will advise each other if required. With new buddies or some of my air hog buddies I will check regularly. Often with insta buddies or one of my "proud" dive buddies I ask to see the gauge, particularly if I'm in lead, as have been lied to.

 

[DevonDiver]

Do you check everybody, or just people unfamiliar to you, or people who are new divers or otherwise seem to merit closer monitoring?

I check more regularly when I have students, especially when those divers are being pushed further to the limits of their comfort zones (rec and tec courses). I've noticed that gas consumption can vary greatly when divers are task-loaded, especially in training and/or when dealing with new equipment, new skills and new environments (overhead).

Do you check multiple times, or just at the beginning, or middle, or toward the end?

I check team gas on descent, at the bubble/descent check.

I primarily dive sidemount. That means I reg-switch every 30bar. As a routine, I confirm team gas every 4 switches - this means at 120 bar consumed (tends to correspond to approx 1/3rd gas supply used).

I check team gas at primary tie-off for any penetration, also before any major restrictions.

I check team gas at turn-points. We assume the diver with highest consumption will make the turn (thus everyone else has more), but that doesn't rule out human error on task-loaded divers.

Does it matter if you have made a gas plan ahead of time?

No. Checks are to ensure the gas plan is working/remains viable.

It's very rare when I'm not in a supervisory/most experienced role in the dive team. When diving with a genuine peer, or even a diver I consider a mentor, then team gas checks are at (1) descent checks and (2) turn-points only.

 

[supergaijin]

Do you check everybody, or just people unfamiliar to you, or people who are new divers or otherwise seem to merit closer monitoring?

While guiding I will only ask for gas if there is an odd-number and I am 'buddied' with someone. Otherwise I say during the briefing that they are responsible for themselves regarding gas- but ask for an indication when half tank and quarter tank are reached.

Do you check multiple times, or just at the beginning, or middle, or toward the end?

If people are close I have a look at gauges while they are checking out something on the reef. I do make a 'remember to look at gauges' signal usually after a few mins in to the dive and we're about to descend deeper on the reef.

Does it matter if you have made a gas plan ahead of time?

For the majority of our shallow dives (12-15m), a half tank signal is enough. When diving deeper then I brief according to what I have seen (consumption) on previous dives. Sometimes ascents are made at 60bar instead of 50 because the reef is a bit deeper. Sometimes half tank would not be appropriate for some divers if they're deeper than 25m- again this is an individual thing.

But in general I expect divers to act like divers. I have had a couple of people run low before- one tried to blame me as I wasn't asking her for signals like other DMs. I explained that she had a buddy and a brain- that should be enough.

 

[Darnold9999]

Typically I travel alone so either dive solo or if necessary with an instabuddy. If I have a buddy, I always ask about 10 to 15 minutes into the dive so I can judge how their consumption matches with mine. If they use more air than I do I will ask again near the time I think we need to think about surfacing/heading back. If they use less then, unless something unusual happens I won't ask again.


Unless the instabuddy is a very new diver I won't ask again in subsequent dives. If the diver is very new, I will repeat for a couple of more dives just so I know what to expect as first dives for new divers in a new location tend to go through their air quickly on the first dive so it takes a couple of dives to guage real consumption.