Think of scuba diving and images of James Bond wearing fins and sneaking up on the villain come to mind.

Coral reefs in Papua New Guinea

Or, maybe your first thought is of Jacques Cousteau investigating the creatures of a coral reef. Both scenarios have entered popular culture for good reason - both reflect the adventure and wonder that characterize scuba diving.

Though many regard Jules Verne's description of underwater diving as pure science fiction, equipment-assisted diving had been around for more than 100 years earlier. But it wasn't until the WWII years when Emile Gagnan, with some help from a then-obscure French navel lieutenant - Jacques Cousteau - invented the first scuba gear, the Aqualung.

Self Contained Underwater Breathing Apparatus (SCUBA) developed rapidly after the war and sport diving arose in tandem. Tanks, regulators and other gear formed the nucleus of an activity that is now practiced anywhere there are more than two feet of water. From the 1960s to the present, buoyancy compensators, wetsuits and drysuits, along with a host of supplemental gear was born or advanced.

But diving requires a lot more than just selecting good equipment. Basic physiology and physics, safety practices, venomous sea creatures are just a few of the essential topics of study. Anyone who 'just wants to get down there' won't be stopped by anyone… but the deep. The sea will claim them quickly enough.

Fortunately, if common sense informed by elementary science is followed, anyone can learn to dive safely. The wondrous enjoyment of diving the seas is then open to all.

Young children can be taught the basics, using SASY (Supplied Air Snorkeling for Youth) and other kid-oriented gear. Teens to the mature can participate in diving and see all that the fascinating coral reefs and ocean depths have to show. Even elderly novices, with proper precautions, can safely enjoy shallow dives and see sights found nowhere else on Earth.

Certification isn't required, but is highly recommended. A good scuba diving class can teach anyone willing to learn in a few hours how to prepare gear, to breath properly, descend and ascend safely and avoid common dangers. You'll learn to clear your mask, use your regulator properly, life-saving tips and much more.

A 20-hour course from a PADI (Professional Association of Dive Instructors) or NAUI (National Association of Underwater Instructors) recognized school can teach you skills useful your entire life. The cost is a few hundred dollars, but certification - once gained - is good for life.

As a bonus, you'll learn to select dive gear. A mask, regulator, buoyancy compensator (BC), dive watch or computer, air supply (snorkel or tank) and fins are essential. But you'll also learn to judge wetsuits and drysuits, knives or guns, and you can even pick up a lot of tips about underwater photography. Instructors are always experienced divers, not just chalkboard jockeys.

The instructors and students you meet will often have useful suggestions and fascinating stories to tell about the exciting places they've dived. Australia's Barrier Reef, Bermuda, the Bahamas, Virgin Islands, Caymans, Thailand and dozens more sites around the globe have all been explored.