Scuba diving (diving with Self-Contained Underwater Breathing Apparatus) is an activity that can be undertaken and enjoyed by practically anybody. However, you will enjoy it more if you are aware of your own limitations, learn to recognise them and stay within them. Diving can certainly offer fun and adventure, as long as you respect the safety rules and accept a degree of responsibility towards your diving buddies. Diving is not a solitary pursuit; it is safer and more enjoyable when shared with others.

There is an element of risk inherent in diving as in other adventure sports, but this risk is reduced to acceptable limits by the observation of basic safety rules and the acceptance of the need for sound training.

Diving will make certain demands on the body, so it is important to maintain a good level of physical fitness. This does not mean athletic prowess or superhuman physical strength. The sort of fitness most useful to the diver is the ability to expend energy in a slow, controlled way, usually keeping some in reserve for emergencies. The fit diver will also suffer less from the effects of cold or extreme weather conditions.

People dive for different reasons. For some, the opportunity to enjoy a contrast to their everyday life is sufficient attraction. The undersea world is quiet; it allows movement in three dimensions; it supports a totally different range of plant and animal life and it enables the diver to enter, for a brief period, another medium. Many people are amazed at the profusion of life and colour found in the seas, not just in tropical waters but also around temperate coasts. Colours will often be muted by the filtering effect of the water but can be instantly restored by using an underwater lamp. The range of life which the diver can study underwater extends from the microscopic to the largest mammals on earth. Diving is not restricted to coastal sites or the seas either — any appropriate body of water can be explored by the inquiring diver. Inland fresh water locations have a quite different nature, and often allow valuable experience to be gained closer to home before visiting the sea. Rivers can be rich in archaeological finds, and some unique discoveries have been made in old wells.

For other divers the fascination may be to search for evidence of past events in this least explored part of our planet. The remains of ancient civilisations have been discovered and brought to the surface by divers in many parts of the world, filling in gaps in our knowledge of the ancient world and opening up many new avenues of research. Shipwrecks hold a unique fascination for the exploring diver and also attract a variety of undersea life, making them perhaps the most enjoyable of dives.

For many of us, the need to take a break for a while and experience new things is very strong. Diving adds purpose to your travel and can bring wonder and adventure to a holiday.

However, there are some people for whom diving is more than just a pastime. The world's increasing need to exploit the resources of the sea is involving more and more people in research under the surface in a wide range of occupations. Some will study the cycle of life and the part each organism plays within the system, while others play a role in extracting the energy and mineral resources that lie below the seabed.

Human beings have been diving since primitive man was forced to forage for food in the sea. In the past, discovery of valuables from shipwrecks provided the impetus for a number of experimental diving devices, culminating in two effective forms: the diving bell, in which divers could spend periods submerged; and the diving helmet, invented by Englishmen Charles and John Deane of Whitstable in 1829.

The history of sport diving can be traced more directly to the invention of the first autonomous diving apparatus, which did not require lines and air hoses to the surface. This new concept was pioneered by William James, an Englishman who, in 1825, produced a workable design in which compressed air was carried in a circular iron reservoir around the diver's waist. We have no record of James diving, so the credit for the first independent apparatus that was actually used must go to an American, Charles Condert, who built and used a horseshoe-shaped waist-mounted reservoir, which provided a continuous flow of air to a flexible helmet. Condert dived with this equipment many times in New York's East River.

The next breakthrough was made in 1865 by two Frenchmen, Benoit Rouquayrol and Auguste Denayrouze, whose lightweight design included a metal canister charged to a pressure of 40 bar. The air supply was now carried on the diver's back. Their most important invention was the demand regulator, which enabled the diver to valve his air at the same pressure as the surrounding water. The apparatus was marketed for sponge and wreck diving. Another important pioneer was Commandant Yves Le Prieur of the French Navy, who was the first to consider amateur sport diving in the sea. He produced a lightweight, compressed-air apparatus with a regulator that was not quite fully automatic. He initially used the equipment with goggles and later with a full face mask. In 1935 he founded the first diving club to train with his apparatus in Paris.