“Scuba” is short for “self-contained underwater breathing apparatus”.
It covers any system that lets you breathe underwater without the need to be connected to an air hose.
Scuba diving gives you the freedom to explore the depths as if you were an underwater animal yourself – albeit a slow and goofy-looking one.
If you are thinking about going scuba diving but don’t really know anything about it, this is the perfect primer to get you started.
Health Requirements

Before anything else, you need to be generally fit. Upon starting a course, you will be requested to sign a medical form in which you declare to be fit to dive.
If you are of senior age, obese, have heart problems, a respiratory condition, diabetes, or epilepsy, then you should certainly seek advice from a general practitioner as he is the only one who can assess your condition.
This isn’t an exhaustive list of conditions. Pregnancy and claustrophobia would be two more examples. Whatever underlying conditions you may have, check if they are compatible with scuba diving.
This is for your own safety, but also for your instructor’s safety, since if something goes wrong it can be very difficult to receive help.
Equipment

Scuba divers are known for the equipment that makes it possible for them to survive under the water for hours, but what is on the list exactly?
Let’s start with the wetsuit. This is a bodysuit that traps a layer of water between it and your body, creating a warm insulating layer. This lets you spend time in moderately cold water without suffering from hypothermia or the other negative effects of the cold.
Wetsuits come in a variety of thicknesses. To dive in icy conditions, you would need a drysuit. This suit is sealed, there is no water coming in and you keep yourself warm by wearing an insulating undersuit.
Next up we have “BCDs”, or buoyancy control devices. This is usually an inflatable pack that you can use to adjust how floaty you are. A weight belt or integrated diving weight pack also makes up a part of your buoyancy control system.
At the surface you should inflate it completely, so you will actually float comfortably. With this system you can also be neutrally buoyant, which is almost like being in zero gravity.
You have a cylinder with compressed air on you. The regulator system (also called octopus) is the device that helps you to breathe from that cylinder. It has a mouth piece and will reduce the high pressure in the cylinder to a breathing pressure.
You’ll also need a pressure gauge, which shows how much gas is left, as well as a dive computer, which shows your current depth and other crucial information for a safe dive.
Last, you need to have a diving mask, snorkel, and fins. The mask lets you see clearly underwater and protects your eyes. The snorkel lets you breathe air from the surface before and after a dive so you can save some air in your cylinder in case you need to make a longer surface swim. The fins attach to your feet and let you swim in an energy-efficient way, since conserving air is important.
Training

Scuba diving is complex and requires quite a few technical skills (as well as a calm personality). It’s not something you can do without training, and no one is going to sell scuba equipment to an untrained person.
The bottom line is that you should absolutely go to a dive school in order to learn how to scuba dive safely. These schools will have certified instructors and specialized dive pools that are deep enough to simulate what diving in the real world is like.
Most importantly, they have people on hand to help if something goes wrong, until you learn how to deal with emergencies yourself.
Certification
It’s important to think of scuba diving as the same sort of responsibility as driving a car. When you drive a car, you take both your own and other’s lives into your hands.
The same is true for scuba diving. If you don’t know what you’re doing, you could end up losing your life or failing to provide assistance to someone else who is diving with you.
This is why you’ll have to be certified to dive. Your dive school is the place to get detailed information; the exact certification may differ from one country to the next.
In general, you’ll first aim for an “open water” certification, which is what you need to go reef diving or do any diving where there’s open water above or around you. You will be limited to about 18m of depth, and part of the course is also theoretical. You will have to study at home and take tests and an exam.
If you want to go diving very deep, inside shipwrecks, or in caves, you’ll need a technical certification and specialized equipment. The same goes if you want to pursue a career in underwater welding or rescue diving. There are certifications for progressively more dangerous and complex diving disciplines, like using rebreathers. You should take this very seriously.