Midway through the course of the 48th annual Waikiki Roughwater Swim, Valisa Saunders was swimming with a friend when a Hawaiian green sea turtle swam between them.

It was a huge turtle, about 3-1/2 feet long, said Saunders, 63, as she stood on the beach near the Hilton Hawaiian Village after she completed the 2.4-mile race.

Captivated by the sighting, they stopped during the race. “We wasted at least 15 to 20 seconds there. We didn’t care,” she said.

“That’s what we love about ocean swimming … the sea life,” she said.

Saunders was among over 700 swimmers who participated Monday in the event, which starts at Kaimana Beach, also known as Sans Souci Beach, and ends at the beach off the Hilton. More than 600 finished the race.

The event’s participants included enthusiasts who traveled with their friends and families from Japan, Australia, New Zealand and the mainland to compete, said race director Kaia Hedlund.

Swimmers ranged in age from 8 to their 80s.

During the race, one Hawaii resident ran into trouble and was taken to a hospital.

For Saunders, this is about the 30th time she competed in the Waikiki Roughwater race.

The first time was when she was visiting from California in 1981. She moved to Oahu in 1984.

“It’s a very tricky course,” Saunders said. “The currents are very hard to predict.”

She added: “You have the surf to deal with on your way in. Swimming in the channel is the hardest thing because the water is going against you.”

Ocean conditions were about 2- to 4-foot waves (Hawaiian scale) and winds were light, said meteorologist Matthew Foster of the National Weather Service.

About 14 lifeguards hired by event organizers monitored swimmers using personal watercraft. More than 90 volunteers that consisted of kayakers, stand-up paddlers and surfers donned hot pink rash guards and watched over the swimmers.

According to Hedlund, about 40 swimmers were unable to finish the race. Some were either plucked from the ocean by lifeguards because they didn’t reach the halfway point at a designated time and others were too tired to finish.

There were conflicting reports on the number of people brought to shore. Emergency Medical Services spokeswoman Shayne Enright said Ocean Safety lifeguards assisted about 75 swimmers after they were unable to finish the race.

One male swimmer described to be in his 60s to 70s suffered cardiac arrest in waters off Kaimana Beach. Lifeguards hired by event organizers brought the unresponsive swimmer to shore just after 9 a.m.

Ocean Safety lifeguards as well as fire rescue crews and Emergency Medical Serv­ices performed advanced lifesaving procedures. He regained a pulse and was taken to an area hospital in critical condition.

Last year, lifeguards assisted some 200 swimmers due to strong currents.

This year, Betsy Jordan, 80, of San Diego, who has participated in the race several times, said the current pushed her out during the last segment of the course as she swam toward the Hilton.

At one point, Jordan said she was swimming in the same spot for awhile. “So you’re thinking, ‘I just went over that rock three times already and here it is again,’” she said with a laugh.

“But eventually you figure you’re going to get in, so you don’t worry about it,” Jordan said.