(CNN) Open-water swimmers are a unique breed. They flirt with danger while maintaining a calm resiliency that would serve nearly any difficult challenge. You can identify the species by their especially fit frames and foam neoprene markings.

This adventurous yet disciplined breed tends to migrate toward certain areas of the world, with South Africa as one of the most habitable for them.

The country, and Cape Town specifically, has gained a reputation as one of the great capitals of adventure sports, including but not limited to climbing, surfing, mountain biking, triathlons, river rafting, hang-gliding and long-distance open-water swimming.

If you're addicted to the secretions of your own adrenal glands, there's no shortage of ways to get your fix in South Africa.

The geography provides a lot of these opportunities. There are more than 1,800 miles of beautiful coastline, stunning cliffs, mountains and lakes. And that diversity extends to water temperatures sought by ice swimmers, those who prefer more tropical seas and all degrees in between.

South Africa is home to two of the best-known open-water competitions in the world, the Midmar Mile (the world's largest in terms of participants) and the Freedom Swim , a series of charity races spanning the 4.6 miles between mainland Cape Town and Robben Island, where Nelson Mandela and other apartheid-era political prisoners were held.

One of the newest in the local race circuit is the Walkerbay Open Water Xtreme , which runs along a small stretch of South Africa's beautiful, dramatic coastline.

Free-range swimming

Open-water swimming, also known as "wild swimming," can take place in any large natural body of water: Oceans, bays, lakes and rivers all count.

Its origin as a distinct organized sport goes back to the first modern Olympics, held in Athens in 1896, in which open-water swimming was an event. Feats of swimming derring-do are even older. Lord Byron captured the world's attention decades earlier when he swam several miles across a body of water now known as the Dardanelles in Turkey.

Over the past 120 years, the tide of new races and newsworthy firsts across various bodies of water has slowly risen. Now there are open-water races of various lengths, conditions and water temperatures all over the world. The recent popularity of triathlons, which start with open-water swims, has further developed the sport from novelty to professionally organized sport. And it's still offered at the Summer Olympics.

There's even an international organizing body, the delightfully acronymic WOWSA (World Open Water Swimming Association). It has a full calendar of races and noncompetitive swims, filtered by lengths, types (relay, eco, charity) and venues (river, lake, ocean, "cold").

Xciting new race

About 75 miles east of Cape Town is the pretty coastal city of Hermanus, a former fishing village now known as one of the top whale-watching spots in the world, especially in the spring months of September and October.

But the town and race organizers invented another reason for tourists to line the cliff and beaches. When there are fewer southern right and Bryde's whales to spot, you can cheer on hearty sea swimmers instead.

Photos: A dramatic open-water swim on the tip of Africa One of the newest open-water races in South Africa is the Walkerbay Open Water Xtreme, which runs along a small stretch of beautiful, dramatic coastline in the town of Hermanus, about 75 miles east of Cape Town. Hide Caption 1 of 12 Photos: A dramatic open-water swim on the tip of Africa The race began at the new harbor after everyone got acclimated in the chilly water. Hide Caption 2 of 12 Photos: A dramatic open-water swim on the tip of Africa Arafat Gatabazi, 22, swims without a wetsuit and finds the cold to be a challenge of mind over matter. "You can control it," he said. Hide Caption 3 of 12 Photos: A dramatic open-water swim on the tip of Africa Close to shore for much of the route but still subject to strong oceanic currents, the conditions are manageable. Hide Caption 4 of 12 Photos: A dramatic open-water swim on the tip of Africa "Hermanus must be one of the most beautiful places in the world to swim," said Vicky van der Merwe, one of this year's competitors. Hide Caption 5 of 12 Photos: A dramatic open-water swim on the tip of Africa The race holds a very small risk of shark attacks. There is safety in numbers when it comes to discouraging sharks from getting close.

Hide Caption 6 of 12 Photos: A dramatic open-water swim on the tip of Africa There are some natural obstacles to negotiate, namely kelp and painful urchins near the shore and at the finish line. Swimmer Paul Ingpen makes his way through the kelp. Hide Caption 7 of 12 Photos: A dramatic open-water swim on the tip of Africa To keep the racers on course, there are buoys and kayakers in the water and lifeguards along the shore. Hide Caption 8 of 12 Photos: A dramatic open-water swim on the tip of Africa Fast swimmers can complete the 2.5-kilometer race in under 40 minutes, but more average ones can take a bit more than an hour. Hide Caption 9 of 12 Photos: A dramatic open-water swim on the tip of Africa Of the 113 swimmers who participated this year, almost all were South African, 39 were women, and they ranged in age from 12 to 70s. Hide Caption 10 of 12 Photos: A dramatic open-water swim on the tip of Africa Naor Lombard, 12, was the youngest participant. Hide Caption 11 of 12 Photos: A dramatic open-water swim on the tip of Africa The race ends at the stone walls and cliff's edge of the town's old harbor and amphitheater. Swimmers are handed hot chocolate to warm themselves. Hide Caption 12 of 12

This year was only the second time the Walkerbay Open Water Xtreme has run, and the first was two years ago. But it has staying power, given the local sport culture and features that make it particularly attractive to racers.

Unlike a lot of open-water races, which may head to an island or go out to a fixed point and return, the Hermanus race runs along its postcard-friendly coast. The town's cliff walk offers excellent viewing along the entire route.

"Hermanus must be one of the most beautiful places in the world to swim," said Vicky van der Merwe, one of this year's competitors. "I've competed all over the world, but Hermanus is special."

Compared with South Africa's many other races and extreme activities, the swim is moderate, only 2.5 kilometers (1.5 miles) long. For many of the swimmers, it's something of a training distance for more truly extreme lengths, such as the English Channel or Robben Island.

The local Atlantic Ocean temperatures are cold, but not so much that swimming without a wetsuit puts runners at an elevated risk of hypothermia. This year, the temperature was 14 degrees Celsius (57 degrees Fahrenheit), a little chillier than normal for that part of the coast.

For those not acclimated to the cold, wetsuits are allowed, and more than half of the participants opted for one. One racer (in a wetsuit) was pulled because of the temperature.

Race day this year, at the end of April, was a cloudy one, with mild to chilly air temperatures and calm waters. Of the 113 swimmers who plunged in, almost all were South African, 39 were women, and they ranged in age from 12 to 70s.

They all entered the water at the new harbor near the Whale Museum, and the finishers exited at the stone walls and cliff's edge of the town's old harbor and amphitheater, where hot chocolate was served to help warm up.

Everyone got in the water first to get acclimated, and then they left all at once, in a bubbling splash of more than 450 limbs.

Close to shore for much of the route but still subject to strong oceanic currents, the conditions are manageable. There are some natural obstacles to negotiate, namely kelp and painful urchins near the shore and at the finish line. The race holds a very small of risk for shark attacks, as incidents in the area are rare, and there is safety in numbers when it comes to discouraging them from getting close.

To keep the racers on course, there are buoys and kayakers in the water and lifeguards along the shore. It may be called "Xtreme," but it's a relatively safe race for newcomers to the sport.

Fast swimmers can complete the length in under 40 minutes, but more average ones can take a bit more than an hour. The prize money (10,000 rand, about $790, for first place) adds some competitive spice for the better swimmers, but most are in it just to finish it.

Open (water) minded

Because most open-water swimmers don't necessarily live near open water, they tend to train in pools, refining a technique (such as minimal kicking) that works for them. Most open water-swimmers utilize the efficient freestyle stroke, also known as the front crawl.

Pools are safer as well, especially if you train alone. Most swimmers, competitive or not -- even those self-taught ones who feel that they are strong swimmers -- benefit from personal coaching to improve form and maintain a training schedule.

The key to being a successful, and safe, open-water swimmer is focusing on general fitness and strength instead of speed. There are no shortcuts; you just have to put in those hours to prepare your body and to acclimate to the temperature of race day.

There are risks, of course. In addition to sea life such as sharks and jellyfish, there is hyperthermia (too cold) and hypothermia (overheating), waves, currents and the mental stamina required to stay focused and avoid panic. The worst-case scenario for any of these is, of course, drowning.

And then there is water temperature. If the water is inhospitable and if race rules allow, newcomers and many seasoned open-water swimmers choose to wear wetsuits. In addition to warmth, wetsuits add buoyancy and make most swimmers faster.

Icy temperatures bring a mental challenge as well. Cold water "breaks your mind into pieces and puts negative thoughts through your head," explained Arafat Gatabazi, 22, who swims without a wetsuit and participated in this year's Walkerbay race. "You have to be mentally prepared and able to use your head over your body, as the body doesn't like the cold, but you can control it."

All the training and risk is worth it, the swimmers will tell you. The physical benefits are enormous, as swimming is arguably the best low-impact cardio and lung workout going. Many a former runner or bicyclist has adopted a passion for swimming after injuring a knee or foot.

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And the mental benefits of open-water swimming border on the transcendent: meditative pacing, deep breathing and being one with the environment.

As Robert Wyland, an artist known for his life-size whale portraits, puts it, "The ocean stirs the heart, inspires the imagination and brings eternal joy to the soul."