It likely is the most scenic open-water swim in the world.

For the past 41 years, participants in the Waikiki Roughwater Swim have battled each other and all that Mother Nature throws at them for 2.384 miles.

It established the distance of what would become the first leg of the Ironman triathlon, the ultimate test for many athletes.

The course from Sans Souci Beach to Duke Kahanamoku Beach takes no prisoners.

Ian Wheeler learned that well last year. The University of Hawaii sophomore made his ocean swimming debut last September in this event, where, despite “getting lost on the course,” he finished 20th.

“This year, I’m not as nervous,” the 19-year-old UH history major said. “Last year, I didn’t have a clue. This time, I feel more confident.

“What I like about the open-water races is they are never the same. There is always new conditions to deal with. There is always something new.”

Race director Kaia Hedlund believes that.

“You never know what to expect,” said the former Chaminade athletic director and University of Hawaii assistant athletic director. “I think it’s a special race, a premier race not only in Hawaii but around the world.

“The sport has exploded, especially since ocean swimming became an Olympic sport (in 2000). Where the North Shore Swim Series used to get 200, you now see 700. It is a pretty hard race, but it’s a great race.”

Hedlund, a competitive swimmer at USC in the 1970s, has been involved with the WRS for the past 20 years. This is her second year as race director, and she has combined her love for swimming with her dedication to the annual Swim With Mike.

The SWM, in its 31st year, is a scholarship fundraiser for physically challenged athletes. It began as a fundraiser for former USC All-America swimmer Mike Nyeholt, paralyzed following a motorcycle accident in 1981, and has grown into a multi-million-dollar charitable foundation.

WRS swimmers can donate to SWM directly or have sponsors. (The public can also donate through the website).

Fifteen members of the UH swim team are participating in Monday’s race as part of SWM, while the other members are swimming laps at UH for a donation.

Some 900 swimmers are expected for Monday’s event. One of them is 54-year-old Rick Heltzel, a former winner who has participated in all but three of the events since 1984 (It was canceled in 2005 due to rough conditions).

“What I enjoy about the race is there is always something different out there,” said Heltzel. “I like the competition. We get some of the best ocean swimmers here.

“I do think the sport is growing, especially with the Olympic movement. And I do think this is the best venue in the world.”

This week’s raging swell has organizers somewhat concerned. But the surf likely will subside by Monday’s 9 a.m. start.

The forecast has swimmers coming into the Duke Kahanamoku Beach finish line with the rising tide.

“The finish is part of the race,” said Wheeler, who won last Saturday’s Duke OceanFest 1-mile swim. “You can be doing well and then someone catches a wave and passes you at the end.

“It is a lot easier in a pool, when all you have to do is look at the black lines on the bottom. In the ocean, you have to find land references, remember to lift your head to figure out where you are, and zone out everyone around you.”

Among the top competitors Monday are three-time defending women’s champion Luane Rowe of Australia and last year’s runner-up, Chip Peterson of North Carolina, the defending world champion.