As a former swimming instructor and lifeguard I had some experience teaching kids to become accustomed to being in and under the water, but with adults things can be a little different. As adults can usually feel more confident about placing their heads under water for extended periods, its usually the children that require more training in this area, but here’s some ideas you could try.
Firstly if you have a bath at home or a shallow pool in which you can lay down in comfortably then when you feel confident practice breathing at a regular pace but each time you breath out, do it under the water so in effect blowing bubbles. Of course its recommended you do this on your front as on your back you will often find the water will run into your nose. If water in the nose is a worry then pinch your nose with your fingers or use a nose clip available at most swimming pools, or sports stores.
As you become used to breathing out under water, you can try to extend the period your face is in the water and eventually include submerging your ears and allowing the water inside. Eventually through practice you will learn to be confident holding your breath under water. To increase the length of time you feel comfortable holding your breath you can practice cardio sports such as cycling which will dramatically improve your efficiency in breathing and your body’s ability to make the most of your oxygen intake. This will greatly increase the time you can spend under water comfortably. I can tell you that with average fitness, gradual practice and gradual confidence building I could manage 150 meters at the bottom of a commonwealth pool on one breath without blacking out, but I would always have a spotter when I was attempting these things. This is just to let you know what is quite possible for an average person so you shouldn’t worry about doing without air for short periods of time.
One other thing you should realise when in the water is how it is only by panicking that you will fail to float properly. Once you feel confident about slightly deeper water, you can try this.
With water deep enough to stand with your head out, but up to your shoulders, being close to the side of the pool for support if needed, you can try floating. Take a medium not large breath and then bring your knees up and your feet off the pool bottom. I would do this in calm water as waves or ripples will move you and will perhaps disturb your confidence at first. As your legs come up and you realise you are floating you can begin to breath naturally with your head out of the water of course. Keep your chin up and look at the ceiling or sky. Your head controls your float angle and if you look down you will probably tip towards the water face down. Breathing out you will notice that you are sinking, so without releasing all of your air take another breath. The reason I advice against taking huge lungfulls of air is that when you breath it all out then the distance you will rise and fall with breathing will be significant and will build a rhythm or large up and down movements which can on exhaling send your chin to the water level. Just breath normally again and any time you feel like you are going too close to the waterline then take in more air in your next breath. Practice this until you are confident that you can control your flotation by simply breathing.
- Breath normally taking more air when requiring more float. Don’t overdo the breathing by breathing too fast as you can hyperventilate.
- Keep the head back and you’ll maintain a stable position.
Your legs and feet may even come up towards the surface putting you in a horizontal position when you have your head back. If you can, don’t fight it as this is perfect. When this happens and you realise you aren’t sinking then you can always revert to this position later when practising swimming if your stroke isn’t working out for you. Horizontal positioning is always necessary to learn a swimming stroke so this is exactly what you should be aiming for. It is normal for fully grown males however to experience heavier legs than torso, so completely horizontal floating is difficult to achieve. Women and children can achieve this more readily as they tend to have less dense leg mass and more fat.
Those are couple of basic exercises you can begin with. Let me know if it helps and when you can progress further.