For the first nine months of our lives, we humans exist in an aquatic environment very similar to seawater. If a human infant is submerged underwater, it instinctively holds its breath for up to 40 seconds while making swimming motions, although we seem to lose this ability as soon as we commence walking. Awakening these reflexes is one of the most important elements of freediving, thus giving humans better abilities to be protected at large depths.
The word Apnea derives from the Greek word a-pnoia literally meaning “without breathing.” The origin of this word doesn’t have connection to water, but in modern athletic terminology “Apnea” has become a synonym for freediving. Apnea means diving on one breath of air, without using equipment that would make it possible to breathe underwater.
In the 16th century people began to use diving bells supplied with air from the surface, probably the first effective means of staying under water for any length of time. The bell was held stationary a few feet from the surface, its bottom open to water and its top portion containing air compressed by the water pressure. A diver standing upright would have his head in the air. He could leave the bell for a minute or two to collect sponges or explore the bottom, and then return for a short while until air in the bell was no longer breathable.
In 16th century England and France, full diving suits made of leather were used to depths of 60 feet. Air was pumped down from the surface with the aid of manual pumps. Soon helmets were made of metal to withstand even greater water pressure and divers went deeper. By the 1830s, the surface-supplied air helmet was perfected well enough to allow extensive salvage work.
Starting in the 19th century, two main avenues of investigation — one scientific, the other technological — greatly accelerated underwater exploration. Scientific research was advanced by the work of Paul Bert and John Scott Haldane, from France and Scotland respectively. Their studies helped explain effects of water pressure on the body, and also define safe limits for compressed air diving. At the same time, improvements in technology, including compressed air pumps, carbon dioxide scrubbers, regulators, etc., made it possible for people to stay under water for long periods!
Scuba diving has come a long way since then, but it’s still one of the most beloved and adventurous recreational activities of all time!