Courtesy of WOWSA, Huntington Beach, California.

The world has innumerable difficult open water swimming competitions. But that is part of the challenge and allure.

Rough conditions, cold water, sharks, jellyfish, tides, currents, long distances, high altitudes and logistical considerations are the primary obstacles. Everyone has a weakness when it comes to open water swimming. Weakness may come in the form of swimming through rough water and waves. Or it might present itself in cold water and hypothermia. Or it might be the fast pace and physicality of one’s competitors.

Besides the really long marathon swims in cold water, what are some of the toughest short open water swims around the world?

While many people can agree on the marathon swims are the epitome on the difficulty scale, it is more subjective and more difficult to identify the relative difficulty of shorter swims. Below are 10 events around the world worthy of consideration based on the following criteria:

1. Competitiveness (speed and navigational IQ) of swimmers
2. Turbulence and unpredictability of water conditions
3. Size of the field
4. Course layout
5. Intangibles

1. Travessia dos Fortes (Brazil): Travessia dos Fortes is the most popular open water swimming competition held at Copacabana Beach in Rio de Janeiro where the mass start is fierce and fast. The race was established in 2001 by the Brazilian Army and is a 3.8 km course with the start at Forte de Copacabana and the finish at Forte do Leme.

2. RCP Tiburon Mile (U.S.A.): RCP Tiburon Mile is a coolish, highly competitive 1 nautical mile race across the tidal flows of San Francisco Bay. The mad-dash at the start is comprised on flailing arms and legs and splashes. The 300m sprint is followed by a dog leg left towards the unseen finish, unmarked by buoys. The correct line across the Bay with the Golden Gate Bridge in the distance, is completely unknown by all.

3. Byron Bay Property Sales Ocean Swim Classic (Australia): Byron Bay Property Sales Ocean Swim Classic is a 2.5 km around The Pass to the Main Beach at Byron Bay, one of the world’s top 100 beaches. Located in New South Wales, 772 kilometers (480 miles) north of Sydney, it can have wildly variable conditions.

4. Waikiki Roughwater Swim (U.S.A.): Waikiki Roughwater Swim fights across 3 tangents along the 3.8 km course offshore from Oahu in the middle of the Pacific Ocean. The winds and currents can create havoc on the first 2 legs, but it is the final 800m leg that requires local surf knowledge or extensive experience to minimize the oncoming currents.

5. Freedom Swim (South Africa): Freedom Swim is 7.5 km from Robben Island to Big Bay, known for its cold waters, rough conditions, waves, and sharks. The presence of known apex predators and cold water makes this a mental challenge as well as a physical one.

6. Bosphorus Cross-Continental Swim (Turkey): Samsung Boğazıçi Kitalararasi Yarislari begins with mass starts and crosses the Istanbul Strait from the Asian shore to the European shore in a non-lineal fashion as the current flows across the 6.5 km course.

7. Fiji Swims (Fiji): Fiji Swims 2.7 km course starts on a disappearing sand bar and takes all types of turns and cuts across the channel between Treasure Island and Beachcomber Island. Water flows depend on the configuration and depth of the coral reefs, combined with the current direction. Marine life is abundant, sometimes swimming with you, sometimes against you.

8. Cole Classic (Australia): Cole Classic is a typical Australian coastal race with beach surf, swells and currents to negotiate as well as facing fast competition and navigating six different directional changes in its 2 km course.

9. Xiamen-Kinman Swim (China-to-Taiwan): Xiamen-Kinman Swim is a 7.1 km cross-channel two-person relay swim between Xiamen, China to Kinmen, Taiwan across the Taiwan Strait, formerly known as the Black Ditch. Winds can generate serious and relentless whitecaps and lateral surface flows that lead to anticipated times to double.

10. FINA World Championships 5 km (various locations): World Championships 5 km is nearly an all-out sprint for 50+ minutes against the fastest swimmers in the world. Every buoy presents a critical turn where valuable seconds and precious meters can be lost or gained. Physicality is maximized with elbows, scratches, hits and bumps throughout while yellow cards and red cards are frequently called.

While every open water swim can be hectic on race day, the reverse is also true. Turbulence the day before the race can turn to tranquility on race day. Tower 26 founder Gerry Rodrigues accurately summed up the vagarancies of the sport. “I never really had any hard swims, just tough conditions at times due to wind, chop, currents, surf, etc. But I will state that one way I prepared for tough conditions was by training in open water in the afternoons and evenings when winds are up. [This] makes conditions challenging and helps build power for the open water.”

Alex Kostich, one of the world’s most traveled and experienced ocean swimmer, recalls his favorites. “I would say the most competitive, challenging, cold and strategic – hardest in that way – would be the RCP Tiburon Mile with a close second being the Waikiki Roughwater Swim.”

Trent Grimsey, the English Channel record holder, who has done professional marathon swims and dozens of world-class ocean swims on five continents, recalls his experiences. “In terms of hardest – the Freedom Swim in South Africa was by far the hardest I have ever done. 11 degree water and in great white shark territory. Not only is the Freedom Swim physically hard, but also mentally hard.”

Rhys Mainstone, a top professional marathon from Australia who has traveled the world, favors a domestic event in terms of difficulty. “I don’t really know the hardest race, but a challenging swim is the Byron Bay Winter Classic. It’s around 2.5 km around a bay; sometimes, the race is nice and smooth and other times it is rough, windy and cold.”

While the above races are relatively short, the World Open Water Swimming Association selected 15 tough challenges in both the Northern Hemisphere and Southern Hemisphere:

1. Kaieiewaho Channel: 72 miles (115 km) of huge ocean swells, aggressive sharks (Tiger and Great White Sharks), warm water, box jellyfish, Portuguese man o war and strong currents between Oahu and Kauai in Hawaii.

3. Farallon Islands: 30 miles of ocean swells, extremely rough conditions, cold water (10-15°C or 50-59°F), presence of Great White Sharks, strong tides, the Potato Patch.

3. North Channel: 21 miles (33.7 km) of cold water (10.5-14°C or 50-54ºF), jellyfish and unpredictable tides, currents and harsh winds between Scotland and Ireland under foreboding skies.

4. English Channel (two- or three-way crossings): 21 miles (one-way) of shifting tides, cool waters, currents, turbulence and marine traffic in the showcase theater of marathon swimming, a key leg of the Oceans Seven.

5. Bering Strait: A 53-mile (85 km) stretch between Russia and the USA located slightly below the polar circle where extremely cold water (under 6°C or 43ºF), strong tides and currents punish its challengers for 2.2 miles between Little Diomede (U.S.A.) and Big Diomede (Russia).

6. Lake Pumori: a glacial lake up in the Himalayas 17,000 feet (5,300 meters) in altitude that requires a hike up and down Mount Everest to reach the freezing water of 32°F (0°C).

7. Isle of Wight: the 90 km (56-mile) circumnavigation of the rough island off the English coast demands endurance, cold water acclimatization and exquisite timing to avoid strong adverse tidal conditions throughout the swim.

8. Okinawa-to-Taiwan: 120 km (74.5 miles) of rough conditions, whitecaps, strong winds, unpredictable currents, aggressive sharks (Tiger Sharks, hammerheads), jellyfish and Portuguese man o war between Yonaguni Island, the southwesternmost part of Japan, and the eastern coast of Taiwan.

9. Cayman Islands: 67.2 miles between Little Cayman and Grand Cayman in the Cayman Islands. Warm water, aggressive sharks (including the Oceanic White Tips), jellyfish, Portuguese man o war, tides, ocean swells unrelentingly pummel its aquatic challengers.

10. San Nicholas Island: 69.3 miles of unforgiving ocean swells, extremely rough conditions, cold water (10-15°C or 50-59°F), Great White Sharks, strong tides, punishing winds and flesh-nibbling sea creatures between the outermost California Channel Islands and the California coast near Santa Barbara.

11. Lake Tahoe: 21.2 miles (34 km) at 6,225 feet (1,897 meters) in a large freshwater lake high up in the Sierra Nevada range in the western United States between the states of California and Nevada. Strong winds and consistent surface chop make for a long day in one of the Still Water 8.

12. Loch Ness: 23 miles (37 km) of cold water temperatures averaging 50°F (10°C) throughout the Scottish summer season. Known for its deep black and chilling waters, it is part of the Still Water Eight and known for the alleged sightings of the cryptozoological Loch Ness Monster (“Nessie”).

13. Lake Ontario: 31.5 miles (51 km) of variable water temperatures that can change in the matter of minutes due to wind shifts from 50 to 72°F (10-22°C). The United States to Canadian international swim, part of the Still Water Eight, is difficult due to unpredictable wind and currents.

14. Catalina Island: 48-mile (77 km) circumnavigation around the Southern California Channel Island demands endurance, cold water acclimatization and exquisite timing to avoid strong adverse tidal conditions throughout the swim and aggressive sharks.

15. Moloka’i Channel: Also known as the Kaiwi Channel between the islands of Oahu and Molokai, this leg of the Oceans Seven is 26 miles (42 km) of huge ocean swells, marine life including aggressive sharks (Tigers), jellyfish and Portuguese man o war, strong trade winds, relentless whitecaps and shifting tides.

There are many other swims around the Northern Hemisphere from the 103-mile Florida Strait to the Round Jersey swim, but these 15 are mind-bogglingly difficult.

Some of the hardest open water swims in the Southern Hemisphere are listed below, although the potential list is extremely long:

1. False Bay: The 33 km across False Bay from Rooiels to Miller’s Point has eluded many who have attempted it. It has been attempted 22 times with only five successes who have survived the hugely strong currents and ever abundant Great White Sharks.

2. Rottnest Channel Swim: 19.7 km of turbulent waters amid thousands of open water swimming colleagues of rugged stock in the largest marathon swim in the world with categories for both soloists and relays.

3. Cook Strait: 16 nautical miles of strong currents and tidal flows with sharks and abundant marine life. 81 swimmers have conquered the powerful ocean swells, turbulent conditions and cold water (sub-15°C or 59°F).

4. Southern (Antarctic) Ocean: 3 individuals – living legends of the extreme world – have pioneered swims at the bottom of the Earth. But with more and more people regularly swimming in sub-3°C or 37°F), expect more swimmers to take 1 km – 1 mile challenges in the driest, coldest continent on Earth.

5. Robben Island Channel: the infamous island prison sits 6.9 km west of the coast of Bloubergstrand, Cape Town, South Africa. Site of the roughest, toughest annual competition in cold water has plenty of marine life, including sharks, that can give swimmers the shivers.

6. Beagle Channel: Even at its narrowest point of 5 km, the waterway between Chile and Argentina present significant obstacles for everyone but the most hardy extreme swimmers. Besides the cold water (sub-4°C or 39°F), swimmers also face currents, surface turbulence and the dreaded williwaw.

7. Strait of Magellan: Even for ships, this passage between the Pacific and Atlantic Oceans is difficult because of the unpredictable winds and currents. Add the cold water and waves, and this waterway is gnarly and treacherous – too dangerous for everyone but the best prepared and most capable swimmers with expert safety crews.

8. Cape Horn: Long known as a sailor’s graveyard, the southernmost point of Chile is an extremely hazardous place to swim due to strong winds, large waves, strong currents and icebergs.

9. Lake Titicaca: Cold water (56-58°F/13-14.5°F) combined with high altitude (3,811 meters or 12,500 feet above sea level) in the highest lake in the Americas makes for tough swimming. Sitting on the borders of Peru and Bolivia, swimmers need to elevate their game in this leg of the Still Water Eight.

10. Cape Peninsula: 75 – 100 km of rocky shoreline bordering the Atlantic Ocean at the southwestern tip of the African continent. Between the Cape of Good Hope in the south and Table Mountain in the north, swimmers face unforgiving ocean swells, extremely rough conditions, cold water, powerful currents and an abundance of sharks.

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