Aug 2014

Improving Air Consumption

By Mike Waddington

When we go underwater there are only two things that affect your maximum dive time. Your ‘No Decompression Limit’ (NDL) and your air consumption. If you are fairly new to diving then it is more likely to be the latter. Usually air consumption improves over time, the longer you spend underwater the better it will get. This doesn’t really help though if you are not able to get into the water very often. It can be frustrating and slightly embarrassing if you breathe your tank really fast. Frustrating because you want to be able to spend the longest possible time underwater and get the most out of your dive, and embarrassing because you might be on 70 bar while the rest of the group is on 120 bar, and they are all questioning why they had to surface early.

Whenever I teach a course it is very common for one person to come up with 40 bar less than everyone else, or for one person to come up with 60 bar more than everyone else. I always tell the ones with the amazing air consumption that they are cursed, and after most dives they will feel cheated out of their maximum potential dive time. For the ones with the quicker air consumption I will tell them to not worry, as it is very common for newer divers, and then give them a list of tips that can help them to increase their dive time. Below I will share with you guys those tips:

Make sure you are Properly Weighted:

I have seen some horrible weighting practices around the world. It is very common for new divers to be in a slightly upright position, which means when they kick, they kick up towards the surface. I have had people coming to do an Advanced Open Water course with me, who claimed they needed 8 kilos (in board shorts and a rashie) to get down! I will explain this is not right but give them the weights so I can see whether it is true or not, and 90% of the time they are 45 degrees in the water kicking to the surface, the only reason they are not going up is because they can’t, they are just too heavy! All this extra weight takes a lot more effort to swim through the water, and of course the air drains from the tank in only a few minutes! You want to do a buoyancy check if you haven’t been diving in a while, or think that you may have way to many weights on, or if in a new environment (salt water to freshwater, or vice versa).

Make sure you are Properly Streamlined:

You may think that being as streamlined as possible won’t make the biggest difference to you air consumption but it really does. Water a lot denser than air, so it takes a huge amount more effort to move through it. Anything hanging from you just causes drag, which slows you down. More drag means less distance traveled per fin kick. Which means that to keep up with the rest of the group you have to swim harder, using up more air than they are. If you are one of those divers who like to look like a Christmas tree, hanging everything except the kitchen sink on your BCD then you may have found the reason why you breathe so fast. You only need to take on a dive what you really need, always carry an SMB, whistle and a (small) knife. But if you are going photography diving do you really need the wreck reel, and 3 different power torches? Or if you are going into a wreck do you need all of your white balancing slates? Most of the time not really. Anything you do take, make sure it is against your body, not hanging down as this will just cause you to slow down. Also think about all the added weight carrying all that stuff!

Get in the Proper Position:

If you are not horizontal in the water then you are going to use your tank twice as fast. It is common for many newer divers to be in a slightly head up position, which apart from making you not streamlined, will also alter the direction you swim. If you are angled up towards the surface then you will kick towards the surface too. This means you start rising up, and then the air in your BCD will start expanding, then when you realize you have ascended quite a bit and try to swim back down, you forget the air has expanded and try to fight physics! It isn’t going to work, at least not effectively. If you find that you have ascended slightly, get completely vertical, deflate your BCD and drop back down to the depth of the other divers. Trying to swim down with air in your BCD is a sure fire way to run out of air fast! If you have trim weight pockets on your BCD then these can help with getting you in the right position, as they sit just below your shoulders they can help push your top half down a bit in the water.

Slow Down:

It is common for new divers to want to go as fast as possible on a dive to be able to see as much as possible on a dive, but this is counterproductive. Swimming fast will not only make you breathe your air down in only minutes, but you will miss most things! Most of the cooler, more interesting stuff we see down there is either camouflage, hiding under rocks or corals or small. If you swim really fast then you will miss them all! Ok you can pick up the pace a little if you see a whale shark, or manta ray and they swim pretty quickly, but the rest of the time slow down! If you feel you need to swim fast to be able to stay level, then you need to practice you buoyancy more.

Practice Buoyancy Control:

If your buoyancy control is not good, then neither will be your air consumption. If you feel you need some more help with your buoyancy then I would highly recommend taking either the Advanced Open Water course, or the Peak Performance Buoyancy Adventure dive. Either one will give you time with an instructor to watch exactly what you are doing underwater, and give you specific tips to help.

Control your Breathing:

It can really help if you are aware of how much you breathe. When we say breathe deeply it doesn’t mean inflate your lungs as much as possible. What it really means is breathe normally, like you’re sitting in a chair relaxing. It is common for people to breathe rapidly and shallow when first SCUBA diving so we say to breathe deeply to make sure they are not doing this. But as you get more into it the urge for short sharp breaths fade. I like to count when I breathe, I count nice and slowly to five when I inhale, and then exhale to the same count. I have heard many divers like to inhale to a count of five, and then exhale by singing relaxing music into their regulator.

Relax whilst Diving:

If you are anxious you will breathe quicker, it is basic physiology. If at any point you are feeling anxious or stressed, but slow down or stop. Think and about your breathing and then when you feel you have calmed down continue at a slower pace. If you feel you can’t catch your breath then signal to your buddy that you want to go up. Remember SCUBA diving is supposed to be a fun, relaxing and enjoyable experience.

Like I said before the only way to get better with your air consumption is to get into the water more often. But if you think any of these things above apply to you then you may have just found out where your air is going. If you are just worried about spoiling other people’s dives by cutting them short then just let the dive leader know in advance. It is quite common for schools to have or be able to gain access to different size tanks, giving you a little bit more air than the rest of the divers.

‘Improving Air Consumption’ was written by Mike

Check out our free info-graphic for you to download and place in your dive school: Air Consumption infographic

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Mike Waddington

I first discovered diving in 2008 after going snorkeling on the Great Barrier Reef in Australia. After trying diving at a flooded quarry in England I decided to head out to warmer more interesting waters in Thailand where I ended on the Island of Koh Tao completing my Open Water course. Instantly addicted with money to spend and plenty of time on my hands I decided to continue until I became a Divemaster so I could live what seemed as the perfect life.

After that I headed to the Caribbean to an island called Utila to complete my instructor course, I spent several months out there completing the MSDT internship, teaching students and leading dives. This is also where I discovered my interest in the technical side of diving, taking part in equipment repair courses and learning about blending gasses and running compressors.

With all my new qualifications it was time to head back to where it had all started, Back to Koh Tao where I intended on living the dream. Once I arrived I quickly found a job and started teaching straight away. During my time on Koh Tao I took part in all many technical diving courses, learning how to dive with re-breathers, in caves and even going down to 90m/300ft!

Qualifications:

PADI Master Scuba Diver Trainer
PADI/DSAT Tech Deep Instructor
PADI/DSAT Gas Trimix Gas Blender
PADI/DSAT Trimix Diver
TDI Intro to Cave Diver
TDI Advanced Wreck Diver
TDI Inspiration rebreather Decompression Procedures
PADI Professional Videographer
BSAC Compressor Operator
TDI Equipment Service Technician

Dream Dive Locations:

Silfra, Iceland
Cenotes, Mexico
Chuuk Lagoon, Micronesia
Ice Diving in Russia