More than 700 swimmers embarked on the Waikiki Roughwater Swim at 8:30 Monday morning. When it was over, a little more than half finished.
The 2.3 mile race is a test of endurance. It started at Sans Souci Beach and ends at the Hilton Rainbow Tower.
Lifeguards said the surf was between 1-3 ft. and trade winds were 10-25 mph. It was the current that crippled close to 300 swimmers.
"People knew the currents were going to be bad. They chose to swim. In our rules you must be past halfway by 10:30 a.m. So if you're not going to get to halfway by 10:30 a.m. or if you are unable to go forward then they are pulling people out," said Kaia Hedlund, Waikiki Roughwater Swim race director.
Other participants told lifeguards they were just too tired to make it to shore on their own.
"The race itself had it's own water patrol. So we just came in and backed them up. Honolulu Fire came in and helped out as well," said Ian Forrester, Ocean Safety.
Medics treated a teenager for shortness of breath. Another woman was treated after she cramped up in the water.
The strong current took its toll on everyone. Several Olympians swam in the race. Organizers say winning times were 10 minutes slower than they would have been under ideal conditions.
Even though many swimmers didn't finish the race. The event's director believes it was a success.
"Everyone I talked to was very satisfied with the race. It was hard of course. The people that got pulled out were very satisfied with our water safety and our concern for their safety. I'm honestly very pleased with the way it went," said Hedlund