In fact, these days, children as young as eight can join a "bubble-maker" course, while many older participants are getting qualified since there is no need to be more than generally healthy.
The chances are that you will fall in love with the sensation of weightlessness and the intense feeling of peace - emotions that are often balanced by the up-tempo drama of exploring a realm that is both novel and exhilarating.
Divers also become trailblazers, adventurers who head to parts of the world you probably wouldn't consider for any other reason. Few people have heard of Palau, for instance.
This tiny republic is east of the Philippines and has neither incredibly famous ancient ruins nor a culture that has spawned great arts or sciences.
What it does have is the planet's most successful shark sanctuary, and the opportunity to spend time with this endangered creature.
The Siren Fleet is based on the Thai island of Phuket. It runs seven- and 11-day dive cruises on beautiful wooden schooners, both in Palau and in neighbouring Truk Lagoon in Micronesia, the location of one of World War II's most devastating naval battles. This left the sea floor littered with sunken ships and plane wrecks that are now sumptuous artificial reefs.
Dive cruises usually include accommodation, transfers, all meals and diving. Specialist tour operators that can get you to these destinations, and many more, include Dive Worldwide.
Getting started
The main training body is Padi. Depending on where you live, training involves a series of classroom sessions followed by exercises in a swimming pool. To complete any course, you then undertake a minimum number of open-water dives.
An overseas learn-to-dive holiday is far more relaxed and focused on achieving the result in the shortest time. One option is the Red Sea, which is home to the world's northernmost coral reefs.
While visiting many of Egypt's Red Sea resorts is currently not advisable, SeaStar Watersports in Jordan is a good alternative. Here, on the Gulf of Aqaba, you can complete your course in a nice, sunny destination while exploring the superlative underwater scenery.
The Red Sea is home to the world's northern-most coral reefs. Photo / Supplied
Family-friendly
If not every family member is equally keen to be underwater, Oman is a good bet for combining diving with other activities. You can travel to the Musandam Peninsula via Dubai. Once there, children can learn to dive in protected bays or everyone can sail on a traditional dhow.
You might see a whale shark before heading back to Dubai for some fun at the water and theme parks, beach resorts or some retail therapy.
The most famous barrier reef is, of course, the great one in Australia. Spirit of Freedom sails from Cairns to the Ribbon Reefs and into the Coral Sea. Trips are at least three days and prices include all meals and diving.
More distant routes may not be appropriate for young divers, so check with the operator.
This enormous expanse is also a working reef, and more serious divers often find it less exciting than its publicity. Yet combine a dive trip with a rainforest trek, a tour of the Outback or a number of other activities, and you will have a holiday to remember.
Rich waters
There's a reason why many divers fly to the tropics. The band between the Tropic of Cancer and the Tropic of Capricorn is where the majority of accessible marine life lives.
The closer you get to the equator, the richer the diversity.
The Galapagos Islands in Ecuador are up there: M/V Galapagos Sky offers the opportunity to explore this unique environment. From this live-aboard, you should see Galapagos penguins, Galapagos sharks, the Galapagos seahorse and all the species of Galapagos fish. Trips are priced at the upper end of the scale.
Head to the Galapagos Islands to see green sea turtles. Photo / Thinkstock
What the Galapagos Islands lack are colourful reefs. For those, head to West Papua in Indonesia.
The Bird's Head Peninsula has more than 75 per cent of the world's reef-building corals and 1500 species of fish. AquaMarine Diving - Bali organises land-based or live-aboard tours. Bali diving is pretty special too.
Big stuff, small stuff
There is nothing so breathtaking as coming face-to-face with an oceanic giant. Nautilus Explorer departs from Cabo San Lucas in Mexico and, 24 hours later, arrives in the Islas Revillagigedo, where giant Pacific manta rays nudge shoulders with sharks.
There are whales and whale sharks, turtles and dolphins. No sighting is guaranteed, but this is one region where the wildlife seems as inquisitive as the divers.
The Philippines is one of the world's best "muck" diving destinations, a term for marine environments with small reef-building creatures that hide in man-made detritus.
Atlantis Philippines runs resorts in Dumaguete and Puerto Galera. There are seahorses, frogfish and critters such as the mimic octopus, which can display as a lionfish or sea snake.
Underwater romance
The perfect diving honeymoon requires an island with palm trees swaying above turquoise water.
Dutch Saba in the Caribbean is less well known than other islands and consequently more romantic - plus the diving is some of the best in the region. Serious divers can even tie the knot underwater, although ceremonies usually require registration in your home country.
The ultimate destination is the Maldives where most islands have classic Robinson Crusoe-type features.
Take a few steps from your luxury villa to the beach to become part of the underwater realm. The north and west atolls are the least busy and you can spend time with the ocean's gentle giants - mantas and whale sharks.
The Angsana Velavaru resort will conduct an underwater ceremony before cooking a private beach barbecue.
Diving in the Maldives. Photo / Thinkstock
Diving in style
Medjumbe Private Island off Mozambique is the place to splash out on a decadent diving trip. This all-inclusive island is lapped by the Indian Ocean where the sunlight seems to make the reefs glow and fish laze over dense areas of hard corals. The atmosphere on land is equally laid-back.
Indonesia is a vast archipelago with more than 18,000 islands. Straddling the Equator, it is also a diving hotspot with destinations from budget to the very best.
Just a short hop from Bali, on the island of Lombok, the Oberoi is a luxurious tropical hideaway with gorgeous private pool villas and views over the coral-ringed Gili Islands.
Once the haunt of backpackers, the Gilis are also a diver's dream, with easy options for novices as well as more challenging sites.
- INDEPENDENT