Hi SD fans, and welcome back. In this video, I am going to discuss one of the aspects of
diving that I probably get quizzed about more than anything – air consumption. Or more specifically,
how to increase your dive time by lowering the rate at which you empty your dive tank.
There is no magical fix-all solution to this situation, as there are so many factors involved,
but I’ll be sharing a few handy hints and advice which should see you able to extend your dive time
and spend more time with the fishes. For those here for the first time, my name
is Mark, I am the editor-in-chief of the Scuba Diver media brand, and welcome to the Scuba Diver
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How long can you dive on one tank? is one question I get asked more than anything else.
I have to say, it is usually by a non-diver, who has also asked ‘have you seen a shark’, but I also
get quizzed about air consumption by divers of all experience levels too. And I think this is part of
the problem – people get way too obsessed with how quickly they consume their air supply, and
that fixation with how fast the needle drops on your SPG can override everything else on the dive.
Now don’t get me wrong. I totally understand the desire to not be the first person
to signal the instructor or your dive buddy to say you are at half a tank and need to turn the dive,
or that you are at 50 bar and need to surface, but don’t try to compete with other divers – every
person has their optimum breathing rate, and yours might never attain their level whatever
you do. It doesn’t matter whether you are a newbie diver with a few hundred dives,
or an experienced diver with thousands of dives under your belt, chances are there
are always going to be plenty of people out there who just don’t use as much gas as you do.
Believe me, I know. After over 37 years of diving around the world, I am more than happy with my air
consumption. I hit my optimum level about 25-odd years ago, and it has remained much the same
ever since. However, I was left feeling like I had the air consumption of a novice open water diver
on one trip to the Maldives. We were doing two back-to-back channel dives,
which involved us dropping down to 30-odd metres in a ripping current, fighting to get
to the edge of the channel entrance, reef hooking in for 20 minutes or so, and then
finishing with a swift drift to the dive boat. They were exciting, adrenaline-fuelled dives.
Each dive ran approximately 40-45 minutes, and I got back on the boat from dive one with around
80 bar left in my ali 80. As I was swapping out my cylinder so I had a fresh one ready for dive
number two after our surface interval, I noticed our dive guide plonking her kit down in the corner
and leaving it. I didn’t think anything of it until a couple of hours later when we kitted
back up to dive again, she just grabbed her gear and we went diving. Sure enough,
on surfacing from dive two, I had around 80 bar again. Once we were onboard, I asked our guide
how much gas she had left out of interest, and was frankly gobsmacked when she said 70 bar!
She had done two full-on dives on one cylinder! And more incredibly, she was using a smaller ali
63 tank! She was a very experienced Japanese instructor, who had been out in the Maldives
for the better part of 20 years, so she was well used to this type of diving, and her incredible
air consumption rate was also helped by the fact that she was absolutely tiny! To this day I have
never met anyone who has had an air consumption rate as low as she did. Just mind-blowing.
That said, there are some things you can do to aid your air consumption, and nailing these
things will assist with helping you reach your own optimum breathing rate sooner rather than later.
First up, get your weighting right. Nothing pushes up air consumption more than being overweighted.
If you are overweighted, ten-to-one you will not be in a nice flat position,
so you will be pushing through the water like this, which requires more effort,
and thus more gas. Even if you are able to get into a nice flat position when you are
overweighted, your BCD will be inflated, so you are still going to be pushing
more mass through the water. When you are correctly weighted – that is,
with the least amount you can get away with – this reduced resistance will help your air consumption.
I mentioned it before, but your actual body position in the water is vitally important.
If you are ‘in trim’, nice and flat, so are streamlined to push through the water,
you will use less gas than if you are finning along like this. Basically, it is a case
of moving around your weight positioning, how high or low your tank is on your BCD,
and your actual body position to be able to quickly and effectively get into that nice flat
dive position. If you find your feet and legs are dropping down, try shifting your cylinder up a bit
in your BCD tank bands (but not too high you hit your reg when you look up). If that isn’t enough,
try moving some of your weights – trim pockets on the tank bands are handy for this.
If you find your legs floating upwards, do the opposite – move your tank down a bit,
and if necessary, shift your weight as low as possible. It is all a balancing act,
and it takes practice, but once you hit the sweet spot, there is no looking back.
As well as weighting and body position, your actual dive equipment
can affect your air consumption. If you have a big, bulky jacket-style BCD,
or have lots of accessories dangling off you like a Christmas tree, then that is going to create
more drag than if you have everything tucked away and are in a smaller, more-streamlined rig,
such as a back-inflate BCD or a backplate-and-wing.
If you are diving in warm waters in a backplate-and-wing or a BCD with no pockets,
and don’t want your DSMB and spool, torch, etc, hanging off your D-rings, get some tech shorts
and then you can store all those accessories in the pockets. This keeps you nice and streamlined.
So that’s weighting, body position and dive gear. Now the focus turns to you. Ideally,
you will be in decent fit to dive shape, with good cardio and stamina, but if you are carrying a few
extra pounds from being in lockdown, or haven’t been keeping your fitness level up to task,
then get on your bike, go for a hike, dig out the rowing machine or whatever. Your air consumption
is never going to improve if you are panting like a winded dog after simply fighting your
way into your wetsuit. I am not suggesting you need to be Olympic athlete standard,
but a decent level of general fitness will make a vast difference to your air consumption.
The next thing to talk about is actually breathing. We all do it, day in, day out,
but when you are underwater, that nice, smooth rhythm we have on land goes out of the window.
It doesn’t help that we use our lungs as our primary buoyancy tool for fine adjustments when
we are diving, and these extra inhalations and exhalations can further throw smooth breathing
through a hoop. You can breathe however you want on land, it doesn’t matter – we have a plentiful
supply all round us, but when we are underwater, we have a finite supply in our cylinder. To help
it last as long as possible, you want to develop a nice smooth breathing action. My advice is to
relax and try to get into a slow rhythm – breathe in for a count of three, and then breathe out
for a count of three is a good starting point. Get nice and comfortable with this, and then move up
to a count of four. If you can get up to a count of five or six, then you will be doing well. Don’t
get too fixated on the count, though – being nice and relaxed with your breathing is the main thing.
Also bear in mind that there will be things out of your control.
If you are diving in cold water, then your air consumption will be more than if you were doing
the same dive in warmer waters, as your body will be working harder to keep your core warm,
which will push up your breathing rate. It doesn’t matter if you are in the best
undersuit and drysuit, with drygloves and so on, basic physiology can only be combatted so far.
Equally, if you are fighting against a current, deep down on a wall, or just having to work hard
on your dive for whatever reason, then you will use more air than if you were simply cruising
along a reef in the shallows. It’s not just that you are physically more active and so having to
pump more oxygen around your system, those sort of dives increase your mental workload more, and that
will also push up your air consumption. Experience helps – even when you are on a dive that
more-novice divers might consider quite full-on, if you can find your zen place and stay relaxed,
your air consumption won’t suffer too much. My final piece of advice? I mentioned it before,
but just don’t get too hung up on air consumption. Diving is all about enjoying yourself underwater,
and if you spend all your time below the surface stressing about how quickly you are using your
gas, guess what – you’ll only end up using it quicker. Plus, you are spoiling the whole reason
you are on the dive, whether that is on a wreck, on a reef, wherever. Enjoy your surroundings and
don’t obsess over your SPG. You’ll find as soon as you stop worrying about your air consumption,
it will start to improve dramatically anyway. What are some of your hints and advice
for improving air consumption? Any neat tricks to pass on to your fellow divers?
Leave your comments below, and if you have a question, fire away – if we can’t answer,
maybe someone in our community will be able to. Remember, if you enjoyed this video,
be sure to subscribe to our YouTube Channel, and don’t forget you can grab a free digital
magazine subscription in the description below. As always, stay safe – and if you are one of the
lucky people who lives somewhere you are able to get out and dive, enjoy!