Scuba diving is swimming underwater using SCUBA - Self Contained Underwater Breathing Apparatus. Using a cylinder of compressed gas to breathe (usually air, but sometimes other gases), scuba divers can stay underwater much longer than would be possible by just holding their breath - for hours or even days!

With the assistance of equipment such as scuba masks, breathing regulators, buoyancy devices, fins, and gauges scuba divers can explore the underwater world. Modern scuba diving is very safe and easy to learn. All basic skills can be learned in as little as three days.

Scuba diving is a sport that is practiced recreationally all around the world and can even be a profession. There are many diving jobs such as recreational divemaster and instructor, commercial diver, police diver, scientific diver, and military diver.

Why do people scuba dive?

For some it's the beauty of the reef and the marine life that inhabits it, for others it's the thrill of discovery deep inside a wreck or cave - everyone has a different reason for scuba diving, but most would agree that it's for the sheer enjoyment of experiencing the underwater world, a world so far removed from ours that it will truly amaze you. Whether you want to relax while photographing brightly colored tropical fish, be thrilled by the power and grace of a school of sharks, or make a living working underwater, scuba diving has it all.

Who can scuba dive?

The simple answer is - almost anyone. Scuba divers are aged from 8 years and over and come from all walks of life. Here are some basic considerations:

• Age

  Children as young at 8 years old can start diving with programs taught in the safety of shallow water and aimed specifically at young children. From the age of 10 years old children can be certified as Junior Open Water Divers and those 15 years and older can be certified as Open Water Divers. There are no upper age limits.

• Health

  You need to be in a state of good health. This doesn't mean you need to be super-fit, but you have to be free of any serious medical problems. You'll answer a medical questionnaire when you sign up for a course and if you or your instructor have any concerns you will be referred to a medical doctor for assessment. You will also need to be able to swim and float or tread water.

• Disabilities

  Scuba diving is accessible to people with physical disabilities. Many instructors are trained to provide courses tailored to physically challenged divers and there are diving societies whose primary goal is to facilitate and promote diving for physically challenged people.

What types of scuba diving are there?

There are many types of scuba diving which means there's always something new to do and see. Here are the most popular types:

• Recreational

  Most divers are recreational divers and this is the form of diving that is devoted to having fun. Some divers love looking at fish and coral, but there are also many specialized areas of scuba diving. After Open Water certification you can complete courses in all sorts of specialties including, but not limited to: night diving, wreck diving, deep diving, navigation, fish identification, underwater naturalism, photography, videography, cave diving, ice diving, altitude diving, and rescue diving.

• Technical

  Some recreational divers want to explore the marine world even further than recreational diving equipment and training allows. Technical diving encompasses areas such as extreme deep diving, advanced wreck diving, and advanced cave diving. Technical diving is for very experienced recreational divers and requires specialised training and equipment.

• Commercial

  Commercial divers scuba dive for a living. They build underwater structures such as oil platforms, carry out underwater maintenance, conduct surveys, create maps, participate in salvage operations, and work in many other diving related occupations.

• Military

  Military diving is similar to commercial diving but also involves such tasks as underwater surveillance, mine clearing, and military research. Military divers and scientists have historically been responsible for most advances in dive equipment and dive medicine.

Where do people scuba dive?

You can scuba dive anywhere you can find water. Over two-thirds of the planet is covered by water, so you can dive almost anywhere. Tropical coral reefs tend to be most popular amongst recreational divers but there are also many wonderful things to be found in cold water environments such as lakes, rivers, and quarries.

Divers can be found in all corners of the globe from the tropical reefs of the Caribbean and the Great Barrier Reef, to the world's biggest lake in Siberia - even under the ice of Antarctica. While most dive shops and resorts operate in warm tropical environments it's also common to find local dive centers and dive clubs in most cities around the world - even inland cities with no water.