The idea that people could breathe underwater was once a fantasy. But today, diving has left the realms of imagination and grown into a worldwide sport with millions of followers. Those who take part in it are granted privileged access to a mysterious yet beautiful world, and every dive is an adventure into the unknown.
Since prehistoric times, people have been drawn to explore the incredible world that lies underwater, whether in pursuit of food or lost riches or from sheer inquisitiveness. There is evidence, for example, that people were holding their breath and diving for shellfish by about 3,000 BC.
Despite this long relationship with the undersea world, the human body is not designed to remain underwater for prolonged periods of time. Only comparatively recently, with the development of rudimentary diving bells and helmets from the Middle Ages onward, did it become possible to stay submerged for longer than a single breath allows. During the 18th and 19th centuries, there were remarkable advances in diving technology, such as full diving suits supplied by air pumped from the surface. These advances, which were often spurred on by the lucrative rewards of salvage work, extended dive times and gave access to ever greater depths.
The invention of Aqua Lung in the mid-20th century permitted divers to explore the depths of the world's oceans freely for the first time. This truly remarkable apparatus enabled people to take their own air supply with them when they dive, eliminating the need to be connected to the surface by an airline. The system that evolved from it—scuba—is today widely used in recreational and professional diving.
As scuba technology became better, diving opened up to the general public. What was once the realm of experts and professionals gradually became a sport with global appeal. Even in countries without a coastline, you will find divers who spend time underwater at inland sites, such as lakes and rivers, or who travel abroad to experience the beauty of the oceans. Once you are qualified, you can dive virtually anywhere in the world. Language is no barrier underwater, since divers use standard hand signals that are understood internationally.
It is hard to tell how many divers there are in the world today, but well over a million people qualify each year. Since its inception in 1966, over 13 million divers around the world have been certified by PADI (the Professional Association of Diving Instructors), and PADI is just one of many training agencies. Diving is one of the fastest-growing hobbies in the world today.