The moon has been mapped in detail, but two-thirds of this planet's surface is still unexplored.
SCUBA1 was invented during the second world war by Frenchman Jacques Cousteau, who called it the 'Aqualung'.
The basic principle of scuba diving is to breathe compressed air from a metal tank - with a special 'demand' valve, which allows air to flow only when you breathe in, so that you don't inhale too much and explode. Modern scuba equipment also includes weights and a bouyancy compensator, an inflatable jacket that allows you to adjust your bouyancy, so that you don't plummet to the seabed or spend your entire time thrashing around on the surface.
Diving is becoming increasingly popular as a recreational activity, and dive schools have sprung up wherever people congregate close to large bodies of water... especially in warm tourist resorts. More and more of us are drawn to the idea of swimming with the dolphins, turtles, sharks, giant octopi etc..., or simply checking out the incredible tiny stuff that lives on reefs and wrecks. For some, it's the idea of breathing underwater, for some it's the virtual weightlessness, and for others just the challenge of blowing bubble-rings, which are like smoke-rings, but much prettier.
In the beginning, scuba diving was essentially a military activity, undertaken only by fiercely fit young men with serious objectives, and the equipment was fairly rudimentary. Slowly though, a small number of pioneers began the risky business of diving for fun. As their numbers increased so did the body of expertise and understanding, and serious money was invested on research and equipment development .
In most countries diving was never regulated by governments - it didn't affect anybody else if a diver got himself into trouble; and, in any case, there weren't enough of them in the early days to warrant any attention. Even today, in most countries there is nothing to stop you buying your own gear and jumping into the sea. You will probably die (horribly), but all the same you don't have to pay for a licence if you don't want to.
Diving organisations include the following:
As the sport has became more popular however, various up-and-coming politicians have spotted opportunities to be associated with some really exciting and worthwhile legislation, in the public good of course. In response, a variety of organisations have been formed to regulate the sport without governments having to be too involved, and they now dominate diving around the world. These days diving is very safe, provided you observe the rules worked out by a very dangerous process of trial and error. The diving 'authorities' tell you what the rules are, and teach you to how dive safely; but it is worth remembering that none of them is actually 'the law', and sometimes they disagree about what is safe!
A C-card is not a licence, it's a certification card; but if you don't have one, most dive operators will refuse to have anything to do with you... and rightly so. A C-card is your only proof that you are a competent, safe diver, and that you are not going to endanger yourself or others. This is very important to dive operators, who have to be responsible for their customers; but it doesn't automatically prove that you are fit to be diving.
Unfortunately it tends to work like this:
When you take a dive course the instructor gets paid, the school gets paid and the certifying body gets money for issuing you with a certification card. If you don't pass the course what happens? Less money changes hands, you are discouraged from spending more money and you tell people who are thinking of learning to dive that it's too hard; so they don't spend money either. Consequently, there is a lot of incentive for instructors to pass people who aren't up to the challenge.
Getting a C-card is probably the first step in becoming a competent scuba diver; but it should be seen as such, and not as a licence to go and explore the Titanic. A basic diving certification, usually called an 'open water' course, means that you know just enough to get in the water without drowning yourself or exploding your lungs. You learn the principles and practise rudimentary skills; but a great many certified divers have never dived without an instructor, and couldn't find their way back to the boat without help. Half the fun for new divers is finding their way home. The other half is being dressed in a rubber suit that makes you look and feel very sexy. Everybody should try it at least once.
There is no substitute for experience, and all the big certifying organisations offer ongoing training and speciality courses, which they recommend strongly. These are generally called something like 'advanced diver', 'rescue diver', 'speciality diver' (eg shipwreck, naturalist, drysuit), 'master diver', and 'divemaster'. From divemaster, which is the lowest level at which you can generally work in diving, onwards, courses become fairly tough - right up to teaching the people who teach the instructors; but at the recreational level it's all a game really.
Of course, they have a financial interest in you spending money on more courses, and some of the training is laughably easy, but you do learn something. They are usually a lot of fun too, and often offer more diving for your money than a lot of dive trips. You can also gain experience just by going diving regularly, and that is often just as rewarding, if not more so.
Giving it a go
There are introductory packages called 'discover scuba', or variations on that theme, and the basic deal is that you get to try on the gear and take it for a test drive. It's usually pretty cheap. and it's the best way to find out if diving is something you want to do. In some places, you may be in a swimming pool. In others, such as the Great Barrier Reef in Australia, you are literally swimming in the ocean with a couple of other people and an instructor.
It can be quite scary going underwater the first time, especially if you get claustrophobia. If you do enjoy it, and most do, then a few days spent learning to dive may be the best investment you ever made.