Skin diving for beginners
Skin-diving has become a popular sport. With only the most essential equipment, diving mask, snorkel and flippers, a fantastic underwater world may open up for you. But diving must be learnt, otherwise it can be extremely dangerous, and the greatest danger is the diver himself.
Among the many holiday-makers who spend their summer holidays on the coast of the Mediterranean there are hundreds of thousands who have this basic equipment with them in their luggage. With this very scant equipment the underwater world will be partially revealed to you. Start diving with a snorkel only when you are a good swimmer and have also followed a First Aid course.
Before you start skin-diving on your own — making numerous errors — it is much better, before your holidays, to follow a diving course.
Admittedly, the world under water is new and fascinating to you, but you must be aware of the dangers.
When swimming you must have observed that everything under water is obscure. Our eyes are not suited to looking under water. This is why you should have a quiet look at that world from a boat with the aid of a glass-bottomed box, or from the shore, just like the fishermen in the Mediterranean when they search for lobsters or fishes.
When you buy your basic equipment there are certain things to look out for and the supply is quite varied. The goggles must be provided with rubber edging and the nose-piece must be formed in such a way that it fits closely around the nose. This is extremely important later on for pressure distribution. Sports shops will not mind at all if you try on the various models. A good pair of goggles must hold tightly on to your face when you are breathing in through your nose.
The snorkel consists of a rubber mouth-piece and a straight tube at the end without unnecessary return valves.
The flippers must also fit. It is better to buy them a little on the large side and made of rubber, because they are extremely uncomfortable if they pinch. Professionals take care that the flat part always bends slightly downwards.
Now try out your new outfit in the water. Put the goggles wet on your wet face and be careful that no hairs or parts of your bathing cap are caught underneath the rubber edge of the goggles.
In order to make sure that the glasses do not mist up in the water, try the universal saliva or spit. Do not laugh; even Jacques-Yves Cousteau knows of no better means.
It may happen when you are breathing under water that some water leaks into the goggles, but that does not matter. You go up, press with one hand against the top of the glasses and breathe out through your nose. The water will escape. Then slide the mouth-piece of the snorkel between your teeth. The tube of the snorkel is upright when you lay facedown in the water. If it turns into the water or a wave causes it to fill, then you do the same as a whale; with a tremendous blow you blow the tube clear again.
Now we start on the flippers. It is best to put them on when the water is right up to your hips, so that no sand or small pebbles can get in.
The leg movement — as for the crawl — must be exercised a few times. With one stroke for each three or four seconds you will make good progress.
Important rules to be observed when diving
1 Never dive alone. You must always have a reliable partner, so that you can either dive yourself or look after the safety of your partner, which means that you have to watch each other constantly.
2 Only dive when you feel totally fit physically.
3 The outfit must be tested and approved.
4 Never dive spontaneously.
5 Puff out your cheeks to correct your ear pressure. When your ears ache, do not go any deeper.
6 Never come up with full lungs.
7 Most important of all, keep relaxed and move slowly; excitement causes considerable shortening of the diving time. Japanese pearl divers can stay under the water for up to five minutes, because they economize their energy.
8 Each time you dive progress a little deeper or swim a greater distance. Do not demand too much of yourself in the beginning.
9 Skin-diving without any knowledge of First Aid is highly dangerous. Obtain good advice, so that if things go wrong underwater, you know what to do. You will notice from your ears during the first dive that the pressure increases the deeper you go, until your ears ache. However, this is not too serious; with thumb and index finger you pinch your nose, keep your mouth closed and blow out firmly through your nose. The pain will go at once, because you have restored the air pressure equilibrium. In your head there are tubes which connect the throat with the middle ear.
Diving demands air which is set against the diving time. It is not easy to get under water with full lungs. If you dive with nearly empty lungs you will find yourself suspended in the water after the first few meters. Never dive deeper than two or three meters.
It is better to dive down with full lungs and make a quick turn. Lie relaxed at the surface and breathes deeply. A few powerful deep breaths — instead of short and superficial ones — will increase your performance under water, but do not pump your lungs full like a balloon. Keep your arms stretched forward. With the tip of your tongue close the opening of the mouth-piece of the snorkel so that no water can enter. To train yourself, first dive 2-2.5m (6-8ft).
As soon as you need air, go up, before you choke. At the surface, keep your face in the water and blow the remaining air out through the snorkel. When going up, hold your hands on your neck and turn your face upwards. You will soon get used to this posture.
Diving techniques
Learn to dive in the correct way. Breathe thoroughly and relax. Keep your arms stretched forwards. A few deep breaths are better than short superficial ones. The popular idea that the lungs should be full is wrong.
After having relaxed the trunk is moved down with a vigorous movement. You then pull up your legs and with a powerful stroke with the flippers, you thrust down.
When swimming with flippers the movements start from the hips. The emphasis is on the downward stroke, even though it must not be hurried. The upward stroke is light.
Skin-diving and health
For swimming with flippers over long distances, and regular diving, you must be physically fit. Heart, lungs, metabolism and ear drums must be all right. This sport is not suitable for people with perforated eardrums and people with frequent complaints about the ears or sinuses. Neither should one dive with a bad cold (when the air pressure cannot be balanced), chronic middle ear trouble and inflammation of the additional cavities of the nose or liver complaints.
It is important that you observe certain precautionary rules when diving. If you go long-distance swimming and dive regularly, then start with neither a full stomach nor an empty one. Your last meal must be at least an hour before. The same applies to divers with compressed air cylinders. If you stay under water for a long time (with compressed air) you must be relaxed. A great danger with long-distance swimming is cooling of the body. Because the heat conductive capacity of water is much greater than that of air. The body suffers a considerable heat loss in cool water. When swimming or diving without a suit to insulate against the cold, the body temperature in the water of 16-18° C (60.8-64.4° F) drops in one hour from 37 to about 35° C (98.6-95° F). Stop diving at your first cold shiver.
|
