Heavy on Air

[AllynCarter]

Hi,

I went diving for the 1st time this year at Dosthill yesterday. Only my 8th and 9th dive.
On the first dive, I was a bit anxious and my air usage was very high. I used 180 bar out of a 15l 232 bar cylinder in just 23 minutes, at an average depth of 12m or so. According to my computer, that's an SAC of 51 l/minute.
The second dive was a little better - shallower (around 8m) and less anxious. Even so, I used a 190 bar out of a 12l cylinder in 35 minutes. That's an SAC of 37 ish, which is more or less what I have averaged on previous dives.
This seems like a high consumption - my buddy used much less.
Any tips for reducing consumption would be much appreciated.

Thanks

[Mark Sydenham]

Hi Allyn,

Best advice to reduce air consumption - Quite simply - Go diving more!:)
It's totally normal for new divers to be a bit apprehensive and hence breathe quicker.
As you gain more experience, you relax and your gas comsumption rate falls.

Also worth checking too:
That you aren't over weighted - excess lead leads to more air in drysuit/BC and hence causes more drag = more air consumption.
Likewise, your swimming attitude in the water - the more horizontal the better - again this gives less drag and more efficient finning = less air consumption.

But most of all - relax and enjoy your diving - that will solve the problem by itself! :D

Cheers,
Mark.

[TerryH]

As has been said, it will get better, but a good idea is to get yourself in the
best frame of mind so you dont get aprehensive.

Good divers have fettling sessions, so I always reccommend a sunday for
diving and saturday to get ready. This could mean things like getting a
decent fill from the LDS and allowing a cooldown and topup, rather than an
overquick one on site, pre-dive.

Zip wax the drsuit check the mouthpieces, ensure hoses are ok.
Get a spare mask, spare fin strap etc. If you've got space in the car,
actually set up your kit. Even something as simple as having a matt to
change on takes a small bit of stress away.

Ok so who is your buddy? Is he an experinced diver or one the same as you?
Maybe now is not the time to be doing exploratory type dives, but rather
time to consolodate what you've learned. Having to make decisions
underwater will rack up your SAC, so let a DL take the point and just
follow.

There are loads of other ways of getting better gas consumption,
but before we get into all that, it always the two basics of being ready to
go and not being the leader.

[Gareth]

This is a common query, if you do a quick search you will find numerous queries from new divers about air consumption.

As has already been stated, go diving, your air consumption will improve as you relax & enjoy the diving.

The first problem will be apprehension, you will have an elevated breathing rate which will have a considerable effect on you air consumption.
The second will 'probably' be that you are currently wearing too much weight, making you work harder physically, controlling your bouyancy, & messing up your posture (trim) in the water. As you relax you will be able to remove weight.
The third will 'probably' be technique, it is likely that you are adjusting your bouyancy frequently during the dive, adding air & dumping air.

The simple solution is to go diving, (as has been previously stated,) this will help you relax, & will help you improve your technique. I would also suggest you keep the dives simple & shallow, which will also reduce apprehension.

Gareth

[Scuba Diva]

Don't worry about it. I have a good few more dives than you and my SAC is rubbish at the moment. But I haven't been UK diving that long so just getting used to it and the extra kit.

Shame that the cure is more diving!:D

[TerryH]

Just to add to my post and before we get bogged down a bit.

Have you seen Ramsey's kitchen Nightmares?

Gordon goes in and inevitably the food is awful.

But instead of doing the obvious and changing the food, he first looks at the
kitchen and again it usually ends up with a clean. Then he looks at staff,
runs a standard service and only then starts to think about a change in food.

With existing students who have the odd problem I always delay changing
the kit too much at the outset, instead I look towards the kitchen and the
staff :rolleyes:

Thats preparation and who has been leading. Once thats in place you can
start to look at things like a new menu, which would include kit configs and
weight issues.

Diving in training is always about small steps, but so is changing steps
that have an impact on memory skills, hence the measured approach.

HTH
Tel

[Maria CM]

My air consumption is completely rubbish in the UK - the more I think about it, the worse it gets. The more I think about it, the more I listen to my bubbles. The more I listen to my bubbles, the faster I breathe. The more I do all this, the less I see on the dive. Becomes a vicious circle for me.

I guess eventually I shall get UK SAC down to warm water SAC but if I think about it, it gets worse so I completely ignore it instead. I just bought a bigger tank to cope with it:eek: :D ;)

If you are carrying more air and your buddy fails to notice, they generally congratulate you on your SAC, you feel smug and then use less air on the next dive as a result. :cool:

best wishes,

Maria

[ozone1]

Hi,

I went diving for the 1st time this year at Dosthill yesterday. Only my 8th and 9th dive.
On the first dive, I was a bit anxious and my air usage was very high. I used 180 bar out of a 15l 232 bar cylinder in just 23 minutes, at an average depth of 12m or so. According to my computer, that's an SAC of 51 l/minute.
The second dive was a little better - shallower (around 8m) and less anxious. Even so, I used a 190 bar out of a 12l cylinder in 35 minutes. That's an SAC of 37 ish, which is more or less what I have averaged on previous dives.
This seems like a high consumption - my buddy used much less.
Any tips for reducing consumption would be much appreciated.

Thanks

Don't worry about it Allyn.

It will improve with time. The more you worry over it the worse it
will be.

When you get to about a 1000 dives you will use so little gas that
you acctualy put it back in the cylinder. :D

Worst comes to the worse just twin two 15ltr steels together :eek:

ozone

.

[northern_diver]

yeah, SAC can be a pain to control, my tips though,

-proper, back to basic boyancy check, sort it out-the knowledge its done will possobly even help.

-fine a few instructors/divers you like to dive with and that you are comfortable, then dive with them lots. gets you more used to the water, more dives and also its with people you actually like.

-controlled movements-using your hands and random movements doesnt help and uses more energy, streamline yourself...as much as a diver could be :rolleyes: this also goes for trim.

-know your training well, know your lost buddy protocol, lifts, tows, AAS et al

-know the dive plan, its helps so much when you actually have some idea what/where/who your doing/doing it with i find.

-gain more experience, simple bottom time clocking.

-chill out, people take themselves far to seriously and think that a set way HAS to be followed, do it how YOU want and it should be fine...as long as its not totally stupid, reckless or suicidal.

hope that helps,
john

[John_C]

Hi,

I went diving for the 1st time this year at Dosthill yesterday. Only my 8th and 9th dive.
On the first dive, I was a bit anxious and my air usage was very high. I used 180 bar out of a 15l 232 bar cylinder in just 23 minutes, at an average depth of 12m or so. According to my computer, that's an SAC of 51 l/minute.
The second dive was a little better - shallower (around 8m) and less anxious. Even so, I used a 190 bar out of a 12l cylinder in 35 minutes. That's an SAC of 37 ish, which is more or less what I have averaged on previous dives.
This seems like a high consumption - my buddy used much less.
Any tips for reducing consumption would be much appreciated.

Thanks

Allyn,

New diver = higher sac = norm!

Every new diver has a high sac rate, its par for the course.

As said time and experience will bring it down as you progress.

In 12 months time you'll be amazed how its got better.

[AllynCarter]

Thanks for all the helpful responses. I'll take your advice and continue to dive within my comfort zone.

[ChristianG]

Thanks for all the helpful responses. I'll take your advice and continue to dive within my comfort zone.
A couple of things I would add Allyn,

Jacques Cousteau once said sump'n like "The Silent Sea" but he told a lie. The sea is far from silent, especially for us OC (Open Circuit) SCUBA divers. For us it is actually extremely noisy.

As you know, and I doubt that you were forewarned by your instructor, exhaled air bubbles away merrily - and noisily. So what does this do? It reminds you that you need to breathe whereas, above water, you will often quite unknowingly put a temporary halt to the act of breathing - maybe you're concentrating on something. I always stop breathing, for example, when I hit the shutter button of my camera, sometimes well before that and I have no idea that I'm doing it (except u/w where, today, it's equally automatic anyway).

You eventually get used to all that bubbling noise, as you eventually get to reduce the weight of your weight belt to manageable proportions, as you eventually ... you get my drift.

Incidentally, when I'm in non-camera mode I habitually fin along with my hands clasped behind my back in typical "Duke of Edinburgh" style. Try it, it will definitely help your sense of balance u/w and it will help to make you learn how breath control really works.

[northern_diver]

Incidentally, when I'm in non-camera mode I habitually fin along with my hands clasped behind my back in typical "Duke of Edinburgh" style. Try it, it will definitely help your sense of balance u/w and it will help to make you learn how breath control really works.

incidentally, i was once told off for that by an instructor. i looked at him funny for a bit then stopped doing it :rolleyes:

while i see little real world issue with doing it, and often do it on land myself, one school of thought may be to teach the 'correct' skill first, that been front help hands, across chest or at waist-simulating holding a camera, compass etc etc.

you might even find you like to hold you inflator or AAS or cross you arms. but well, itsnt it more use at the front.

what ever is comfortable ally :)

john

[TerryH]

It's more to do with location then anything else.

Good clear water with lots of finning and hands behind would be fine.

Change that to low viz and the chance of an eroded bulkhead doing a
kebab on you and having your hands out front might be a good
idea :rolleyes:

Thats why hands in front anywhere is better than behind and probably
why you got told off.

[Mike Halligan]

It's more to do with location then anything else.

Good clear water with lots of finning and hands behind would be fine.

Change that to low viz and the chance of an eroded bulkhead doing a
kebab on you and having your hands out front might be a good
idea :rolleyes:

Thats why hands in front anywhere is better than behind and probably
why you got told off.

Terry,

the explanation you offer is excellent when proffered as an explanation, but when abused as the root of a telling-off it invalidates its own worth. Imminent danger apart, no-one at a point of greater knowledge is justified in telling off someone else who would otherwise, from a better mentor, learn something useful. (Unless one counts "Avoid this Instructor" useful knowledge.)

Always be teaching is the maxim, not always be shouting. :D

[TerryH]

Terry,

the explanation you offer is excellent when proffered as an explanation, but when abused as the root of a telling-off it invalidates its own worth. Imminent danger apart, no-one at a point of greater knowledge is justified in telling off someone else who would otherwise, from a better mentor, learn something useful. (Unless one counts "Avoid this Instructor" useful knowledge.)

Always be teaching is the maxim, not always be shouting. :D


Er TBH Mike, No ;)

As Instructors we have a whole armoury at our disposal to teach students
and yes one of them the good old telling off when something is wrong.
For some Individuals this would as you say be very wrong, but for others the
act of "telling off" reinforces any memory skills to make sure that person
doesnt do it again.

The OP talked of a telling off and we have no idea as to what the exact
circumstances or if the OP was one of the ones that this approach works
with. So giving the the instructor the professional courtesy to assume this is
the case I'd still go with a telling off.



PS: Just come back from a Sports Awards night and spoke to one of my
old students. She's very slight and struggled badly with Sports Rescue.
She reminded me of the way that I consoled her when she was crying,
then changed the location for another go the next day and then went all
nasty to the point where she got mad enough to prove me she could do it :D

Day 1 wasnt the time to shout or tell off.
Day 2 was :)

Like I say a time and a place for everything :cool:

[ChristianG]

incidentally, i was once told off for that by an instructor. i looked at him funny for a bit then stopped doing it :rolleyes:

while i see little real world issue with doing it, and often do it on land myself, one school of thought may be to teach the 'correct' skill first,
I have a question (I note Terry's reply). Why would teaching "hands in front" be correct? Surely "what's comfortable" is, just perhaps, more "correct"? Yes I know, today's novices tend to wave their hands around and that is something to be dissuaded. Equally today's novices won't, or at least shouldn't have, other equipment in their hands in any case.

However if a diver that is not carrying something is diving with their hands clasped behind their backs, and someone, in your case an Instructor no less, comes up and says that is wrong I sense a wrong and it is not on the part of that diver.

A diver with their hands behind their back is about as streamlined as it gets (and incidentally proves to me that they have no need for the usual buoyancy controls). So they come up to something hard, guess what? A sweep forward motion from hands behind back will stop you cold. And I do mean cold.

Maybe I'm missing something?

[Sam Johnston]

If the current BSAC hot button is trim and buoyancy shouldn't we be encouraging divers to arrange their hands and arms so as to help them maintain horizontal trim?

[Nigel Hewitt]

If the current BSAC hot button is trim and buoyancy shouldn't we be encouraging divers to arrange their hands and arms so as to help them maintain horizontal trim?
Trim and buoyancy is a fad for quarry divers. :D

Currently, in the Channel, you need your hands to feel where you're going.

[TerryH]

A diver with their hands behind their back is about as streamlined as it gets (and incidentally proves to me that they have no need for the usual buoyancy controls). So they come up to something hard, guess what? A sweep forward motion from hands behind back will stop you cold. And I do mean cold.

Maybe I'm missing something?


Your paragraph above is reffering to a streamlined diver who has full control
of buoyancy and can put hand forward, fast.

The fact we are talking about an instructor - student converstaion
suggests that we are not comparing like for like here. Its a student
and we can assume not experinced.

Even if we dismiss the UK reasons for "out front", its not a good idea
to teach anything that might delay a response, hence this approach.

[northern_diver]

gota say like, i think im with terry, hands in front is a bit more versitile and free to perform and gets you used to them been there for holding various bits of kit.

stream lining is a bit of a micky mouse to some degree in diving, thinking about it when would i have my hands in a situation where they could be front or back...while in transit most likely...so in the sea, in transit, under water...i carry a dSMB reel, taking up that hand....just dont believe in going in the sea with out a surface mark detection aid like a SMB or dSMB (normally), so its front.

when i was told not to, and changed, its because i had a habit of resting my hands under my cylinder while moving, now i hang them on the front somewhere, normally on the chest strap etc or cupped on my AAS on the necklace.

I think i suits my diving, but if were teaching it in years to come...im not an instructor...i would tell my trainee's the pro's and con's and then get on with something a little more important.

john

[Dave Whitlow]

Currently, in the Channel, you need your hands to feel where you're going.
Nigel, you exaggerate! We had 2-3m, maybe even 4m, out of Brighton last weekend. I found the green water very relaxing although it did limit my view ;)

[Nigel Hewitt]

Nigel, you exaggerate! We had 2-3m, maybe even 4m, out of Brighton last weekend. I found the green water very relaxing although it did limit my view ;)
Last sunday but one I was running the club boat and one of the divers insisted it was half a meter but I think he was wrong and it was at least a meter.

We were a bit inshore and I had some poor OD trainee with me on his first dive off the RIB and, I think, his first sea dive.
He thought it was wonderful.

[Dave Whitlow]

Last sunday but one I was running the club boat and one of the divers insisted it was half a meter but I think he was wrong and it was at least a meter.

We were a bit inshore and I had some poor OD trainee with me on his first dive off the RIB and, I think, his first sea dive.
He thought it was wonderful.
That weekend I was at NDAC but last weekend we were on the Pentryct (which I will see one day - maybe!) and Fortuna each with the traditional ledges/reef sequel. It wasn't too bad and was better than doing an inland site (yet again!) but as a first dive would be an amazing experience (not the Fortuna - that would be insane!).

It is all too easy to forget the wonder of those early dives and training does bring some of it back. Last year I took someone into Littleton Pit ("muddly puddle") for their first dive and I came out thinking "yuk!" and he came out raving about how amazing it was. Littleton was my first UK open water dive, although I chose February!

Nigel, thanks for the observation about Wittering as it was they saved us with their gas fills. Shona was very helpful.