Diving is a potentially hazardous activity. Those embarking on underwater activity of any type are strongly advised to seek and observe appropriate professional and local safety advice. The guidance that follows cannot be comprehensive and must therefore be regarded as incomplete.
Do not go diving unless you are fit, confident and suitably qualified. It is also absolutely vital to ensure that your equipment, particularly the regulator and cylinder combination, is in good working condition and has been tested or inspected according to the manufacturer's recommendations. When using unfamiliar equipment, make sure you understand how to use it before diving. If doubt exists, be sure to get instruction. Carrying additional equipment with which you are not familiar can upset diving routine.
Consider using clips for equipment so that hands are free to deal with buoyancy, a flooded mask, etc. Make sure your buddy understands the objectives of the dive, particularly if they are not directly involved in the photography. Consider who will be looking after your buddy when you are concentrating on taking photographs.
Common underwater hazards include corroding metal edges, spikes and nails, all of which can puncture or tear a diving suit and human flesh. It makes sense to dive conservatively. Don't push your comfortable diving envelope at the same time as you are learning new tasks underwater! When things go wrong underwater they become very serious extremely quickly. Divers are surrounded by a hostile environment and the dividing line between a near miss and a serious accident is a narrow one. A minor heart attack soon becomes a death by drowning. A panic attack brought on by inexperience and challenging conditions can swiftly lead to the same tragic result. A diver who rushes to the surface too quickly risks fatal lung injuries, paralysis or brain damage.
Diving struggles to shed its image as a dangerous sport. Part of its allure is the adrenaline rush provided by swimming with sharks, mastering the intricacies of equipment and seeking out remote and exotic locations. It has all the hallmarks of a macho sport, somewhere between mountain climbing and parachuting on the scale of gap-year initiation rites.
For anyone wanting to learn, it is essential to sign up for a recognized course of instruction. The main agencies in the UK that organize diver training are the British Sub-Aqua Club (BSAC) and the Professional Association of Underwater Instructors (PADI). Other countries have their own organizations.
Other organizations such NAUI, CEMAS or SSI may offer suitable courses. Any of these organizations can teach you to dive safely and issue you with a certification card allowing you to dive and hire diving equipment. Beware of organizations which offer very short courses leading to almost immediate certification. Ultimately it is the life of the diver that is put at risk.
A typical diving course teaches basic safety, how to use scuba equipment and share air with a buddy, how to avoid decompression sickness (the bends), how to control personal buoyancy, and how to minimize risk. Accidents do happen, but most can be avoided by adherence to the rules.
A basic diving course takes at least several days and will progress gradually through the basics before moving on to more advanced techniques. Experience is ultimately the greatest teacher, but must be acquired in a controlled and gradual manner. Remember that it is often qualified divers who make mistakes - typically because they become over-confident or too casual.