Scuba gear allows you to be like a fish, though one giving off more bubbles

Swimming is about staying at the surface, organising your breathing so that you dont inhale water, and using your limbs in a co-ordinated way to propel yourself. Its a sport and it requires a degree of athleticism.
Diving is a pastime. If you can breathe, you can dive. Naturally, if you cant swim youll be frightened of the water, and you do need to feel comfortable in water to be able to learn to use Self Contained Underwater Breathing Apparatus (SCUBA). But scuba gear allows you to be a like fish, and you might be surprised to learn that many fish do very little swimming! They just hang around.
Scuba equipment and knowing how to use it safely allows you to dive with your brain rather than your muscles. You dont have to be particularly fit, though you should be in good health. You learn how to use physics to let you do what you want.
So you dont have to be a good swimmer but you do need to be able to swim, to have a calm disposition and to listen to your instructor. Once you have the confidence to use the equipment properly and understand the physics, youll be amazed how your attitude to water changes.
A lot of formerly feeble swimmers have become quite proficient after learning to scuba-dive first.

The open-circuit scuba regulator is a remarkably simple item of equipment. As you inhale, a valve opens and supplies air at the same pressure as your surroundings. Its easy. There is a slight mechanical action but its easier than breathing through a snorkel.
Under water, you will get your face wet, theres no escaping that! You might get some water in your mask, too, but youll learn a very simple method of getting rid of it. You may get some water in your mouth but
getting rid of that is even simpler. Thats what your instructor is there to teach you.
Did you know that you can open your mouth wide under water without the water rushing in You can open your eyes too, without a mask. Your instructor will teach you this as your confidence increases. If you can breathe, you can do it! You just have to be shown how.

When you learn to dive, youll find yourself sitting on the bottom of a swimming pool. It might be a couple of metres. You never did that before. It always seemed far too deep even to swim down there. When you hear about people diving to 100m and beyond, that sounds out of this world, and so it is for most people who go diving.
Once you get comfortable breathing air at the bottom of the pool, you will next find yourself in some confined water which might be as deep as 6m, but by then youll be used to it. It wont seem so deep after all.
Some divers are quite happy in the shallows at less than 10m and could rightly argue that this is where the most colourful undersea life lives. Worldwide, the great majority of certified leisure divers rarely pass the 18m mark. Thats fine, if youre happy seeing everything you want within those limits.
Other divers want to go deeper. There might be a shipwreck they want to see. Some limit their range to around 30m, while others go on to 40m or more. As you become more proficient, and are taught more than the initial basic course, the possibilities increase.
The short answer to the question is that you dont have to go any deeper than you want to.

In the early 1900s a rogue shark terrorised the beaches and a river around Long Island in the USA. Several people died after being savaged. When they were dragged from the water where they had been swimming, and before they invariably died through loss of blood, each claimed to have been attacked by a shark. But would you be surprised to hear that nobody believed them
At that time, sharks had no reputation for attacks on man, and it was only after the animal was accidentally fished out that the truth became apparent.
Peter Benchley based a book on the story. Steven Spielberg made a movie. Now, since Jaws, everyone believes that sharks attack people!
Sharks have teeth. Very sharp teeth. People have teeth too, but dont worry about your diving instructor. He wont bite you, and nor will any shark.
In fact, youll be lucky ever to see a shark. They can be elusive, so much so that around the world there are divers who enter the water with large pieces of dead fish in their pockets in the hope of attracting them. Thats because a shark wont come near a human unless it thinks theres a chance of a risk-free meal - a bit of dead fish that wont bite back!
So why do we hear about the occasional shark-bite on swimmers and surfers
Because they are invariably participating in their chosen activity in an environment where sharks are feeding. Surfers sometimes get mistaken for seals or sea-lions on the surface. Those who swim where anglers are reeling in dead and dying fish are asking for trouble. The vibrations of dying fish are like a dinner bell to a shark, and if the water is murky, as it invariably is near the shore, a shark can make a mistake and bite the wrong thing.
A shark bite can be serious. However, sharks do not predate on people.
If anything, it is sharks that are the victims of humans. More than 100 million are harvested by fishermen every year and there are only a couple of accidents involving shark bites on other water-users, invariably near the shore. In fact, sharks are becoming an endangered species.
Divers tend to want to do what they do in the clear, deep water well away from any beach. Divers dont look like prey - theyre big, noisy, air-bubbling creatures that can scare anything away! Check out our feature What Should I Be Scared Of

That all depends where you are and what youre wearing. Water conducts heat 25 times more efficiently than air, which is why its used in most central-heating systems. Water will conduct heat away from your body if its cooler than you are, and most bodies of water, even in the tropics are cooler. So you need to wear a thermally insulating suit if youre not to get cold at some point.
Selecting the right sort of suit is another subject youll learn about from your diving instructor. You may initially feel comfortable in the swimming-pool with nothing more than your costume but after a bit youll start to get chilled.
Remember that while swimmers tend to swim only for short periods, scuba equipment allows you to stay in the water for hours if you want. Keeping warm is just a matter of selecting the right kit for the conditions in which youre diving.
So how dark is it down there In the crystal waters of the Mediterranean or the tropics, sunlight passes down deep into the water. You can see really well down there, but colours get changed. The water filters out the reds and yellows and leaves behind only the blues. So divers often take lights with them, not because its dark but because a powerful light will show things in their full spectrum of vibrant colour.
In the water in most places round Britain, it can be very murky. It gets quite dark sometimes only a few metres down. It all depends on the conditions prevailing at the time and we cannot depend on strong sunshine. So divers take a light to be sure to be able to read their gauges, to see each other and to be able to penetrate dark recesses of rocks or wrecks. Its not a problem, just a question of having the right tool for the job.

The bends, or decompression sickness, can be a problem for deep divers but one that can be prevented. A hundred years ago there was no real understanding of why it happened. Now we know more.
Divers learn that there is a limit to how long they can stay under water at various depths, and what they must do if they outstay their welcome. They also know that the speed at which they approach the surface from deep water is very important.
When you first learn to dive you wont go deep enough for any of this to be a problem. As your knowledge increases, so will your abilities and the depth you might want to go to. But technology is there to help us. Modern divers have wrist-mounted decompression computers that take care of everything.
All you have to know when you start is that the slower you ascend from every dive the better. If you encounter a problem, rushing to the surface in a panic is not the answer. However, in the pool when youre starting to learn, if you have a problem you can just stand up!

The skills of scuba-diving, once learnt, will stay with you for life. There are people still diving well into their 80s. Experience counts for more than simple strength.
Its a salutary experience for some macho men to find that women can be better divers. Women are less likely to fight a problem than to think through it.
So you can never be too old, but can you be too young Training agencies continually lower the minimum age for learning to dive, in response to consumer demand. Ten is now widely considered by commercial training agencies to be an acceptable age to start learning under controlled
circumstances. Young people learn very easily, and can scuba-dive as easily as they learn anything else.
But diving does go on under water and that is basically a hostile environment. So its down to a parent or guardian to judge whether a youngster has the right attitude, and the appropriate awareness of danger to be safe scuba-diver.
The hazards of scuba-diving and breathing compressed air while yourself under pressure are insidious. The damage from doing it wrongly can be latent. This is not easily appreciated unless you have been trained properly and the threats have been understood. That said, there are plenty of adults who might not be considered safe to let out to the shops alone!
As to health and fitness, there are certain medical conditions that might disqualify you from diving. Besides those that involve difficulties in breathing, anything that might induce unconsciousness would be fatal if it happened while you were under water. So those who suffer from epilepsy for example, or any mental illness, are usually discouraged from going diving.
Before you undertake a scuba-diving course you will be asked to fill out a medical questionnaire or even to be examined by
a doctor. Its in your best interests.
Fitness is relative. If you smoke or are obese, you will live less long than you would otherwise, but it doesnt disbar you from enjoying your life in the meantime.
You can still learn to dive. If you drink heavily, you just have to learn that your first drink of the day denotes that youve had the last dive of the day - and that goes for everyone.

Scuba regulators allow you to breathe normally
Much colourful reef life lies in sunlit shallows
Shark-feeders know that they are not malicious
Divers may go deeper to visit certain wrecks
Suitable clothing - wetsuits or drysuits, hoods and gloves - can keep you well-insulated under water
Using an underwater torch restores the colour that depth removes
Youre never too old to dive!
Professional Association of Diving Instructors (PADI) 0117 300 7234,
Scuba Schools International (SSI) 02032 873988,
Scuba Diving International (SDI) 0777 379 7335,
National Association of Underwater Instructors (NAUI) +31 054 8611 769,
International Association of Nitrox & Technical Divers (IANTD) 01202 861407,

British Sub-Aqua Club (BSAC) 0151 350 6200,
Sub-Aqua Association (SAA) 0151 287 1001,
Scottish Sub-Aqua Club (SSAC) 0141 425 1021,

UK Sport Diving Medical Committee

The Scuba Trust 07985 025385,

Nautical Archaeology Society (NAS) 02392 818419,

British Society of Underwater Photographers (BSoUP) 020 8668 8168,