A note about the author – Simon is the best-selling author of Scuba Confidential – An Insider’s Guide to Becoming a Better Diver and Scuba Professional – Insights into Scuba Diver Training & Operations. Both books are available now from Oceanic Ventures.
Once you have completed your first Scuba course and begin diving with more experienced divers, one of the first things you may notice is how much longer their air seems to last in comparison to yours. You are always running low before the rest of the group and having to cut short your buddy’s dive.
The people who scuba dive with you will not mind at all. They know you are a new diver and it was not so long ago that they were in a similar situation. However, you probably will mind and you will be looking for ways to breathe more efficiently and make your dives last longer.
Here are 10 tips guaranteed to improve your air consumption and also make you a better scuba diver in many other respects at the same time. Notice that none of these involves using a bigger cylinder!
Tip One – Get in the Mood
Take some quiet time on your own before each dive to relax and focus on what lies ahead. Breathe deeply and find a nice peaceful place in your mind. Put away any negative thoughts concerning other aspects of your life. You are going diving; there is nothing you can do about anything else while you are underwater.
Tip Two – Breathe Properly
Learn to breathe like a scuba diver. Breathe from the diaphragm; push your stomach out to allow your lungs to expand and draw in as much air as possible. Then breathe out long and slow, bringing your stomach in to reduce your lung volume to a minimum. Practice this long, deep, slow breathing cycle until it becomes instinctive. Not only will this help you to use less air, it will help you stay calm and think clearly.
Tip Three – Get Fit
Diving is a sport and the fitter you are, the better you will dive and the less air you will use. Start a programme of aerobic training and increase the level of your training as a dive trip approaches.
Tip Four – Don’t Move
When you are underwater, only move your fins when you need to go somewhere. If you are not going anywhere, keep them still. Tuck your arms in, only use your hands if you need to signal and incline your body like a motorcyclist if you want to change direction or regain your equilibrium.
Tip Five – Remove Weight
Like many new divers, there is a good chance that you are wearing too much weight. A reliable indicator of this is if, after your initial descent, you have to add quite a lot of air to your BCD to keep you off the bottom. What happens next is that, when you start you swim, the air in your BCD lifts your upper torso and the weight around your middle drags your butt and legs down. This gives you the head up, tail down posture of a seahorse. Look at other new divers or ask a friend to take a short video of you, to see what I mean. Moving through water in this position requires much more effort and causes you to use up much more air than if you are horizontal, as you should be.
The trick is to reduce the amount of weight you are carrying. Start by removing one piece and, if you can still make a comfortable initial descent by exhaling fully as you leave the surface, remove another. If, at the end of a dive, you can hang at a depth of 10 to 20 ft. with 750 psi in your cylinder and an empty BCD, you are correctly weighted. Another little thing to remember: if you are wearing a weight-belt and a wetsuit, the belt will loosen and slip down onto your hips a little as the water pressure compresses your suit. So, once you are at depth, take a moment to hitch your weight-belt higher on your waist and tighten it a little. This will lift your legs up and give you a more horizontal posture in the water.
Tip Six – Do an In-Water Check
The whole gearing up, entry and descent process can be awkward and strenuous. For instance, you may be wearing a thick suit on a hot sunny day, there may be a lot of other divers around or the sea might be choppy. A whole host of factors can conspire to undo the positive effects of your pre-dive relaxation and the consequent stress can cause you to go through your air more quickly. So, once you are underwater and the confusion on the surface is behind you, make it a habit to pause briefly and go through a quick in-water check. Take a few seconds to compose yourself, get your slow, deep breathing cycle going, inspect your gear for problems and verify your cylinder pressure (Tip Eight) before heading off to the depths.
Tip Seven – Kick Differently
There are a number of easier ways to fin than the classic wide, full-legged scissor kick you used when you started diving. Learn about alternative techniques like frog kicks and modified flutter kicks. Ask your instructors to show you how or just watch and copy what they do. Using energy-saving fin techniques will reduce your air consumption considerably.
Tip Eight – Know your True Starting Pressure
The cylinder pressure you see when you check your gauge on a sunny boat deck is misleading, as the reading changes with the drop in temperature when you enter the relatively cool water. The underwater reading is your true starting pressure. If you are aware of this you can calculate your airtime (Tip Nine) and this will help you relax. A relaxed diver uses less air.
Tip Nine – Always Know How Much Air You Have
Always know how much air you have left and also have at least a rough idea in your mind of how long it is going to last. This is how you do it.
- As you descend, make a mental note of your air pressure, say 2900 psi
- After five minutes at depth, look again. Maybe you now have 2700 psi.
- This means you have used 200 psi.
- Assuming you are diving the deepest part of your dive first, you now know that you will use a maximum of 200 psi every five minutes.
- If you want to surface with 500 psi, you have 2200 psi left to use.
- So a simple calculation ((2200 / 200) x 5 minutes) tells you that you have AT LEAST 55 minutes of airtime left.
Tip Ten – Keep Calm
If you ever find yourself becoming anxious underwater, the chances are that the reason for this is that you have lost your deep, slow breathing cycle without noticing it. Maybe you have been fighting a current or trying to keep up with a buddy who is swimming at a pace that you are uncomfortable with. As soon as you are aware of your increasing anxiety, stop finning. Calm yourself down by inhaling fully and, most importantly, exhaling fully for a couple of minutes. As you take deeper and gradually less frequent breaths your mind will clear. Check your contents gauge. If you still have plenty of air left, continue with your dive. If your air supply is lower than you expected, ascend to a shallower depth. Remember, the shallower you are the less air you use.