SHANGHAI -- Organizers of open water swimming events at the world championships have unveiled a high-tech sonar system to quickly locate any swimmer who drops below the surface.
Safety has become a major concern in the sport after the death of American Fran Crippen in the United Arab Emirates last year.
Crippen, a six-time U.S. national champion, died in October near the end of a 10K World Cup event in warm temperatures. No one noticed him slip beneath the surface and his body was not found until two hours later.
FINA has arranged early morning start times for the races but the water temperature is still expected near the newly recommended limit of 88 degrees.
"It's warm, but I think the athletes are prepared for that," United States open water coach Jack Fabian said. "It looks like the conditions will be within the guidelines."
Racers will be monitored by 12 safety boats at Jinshan City Beach, which is located about an hour's drive from Shanghai. It's a 1-square mile, man-made embankment, with sea water pumped in through a floodgate. The sea water is supposed to turn clear after treatment.
Warm conditions will almost certainly be a factor. A tight 90-degree turn 200 meters into each race could prove more challenging.
"When you have 56 people diving in off a dock straight into a turn, there's going to be some contact. I've never seen that before," said Fabian, whose daughter Eva will be among the competitors in the women's 10-kilometer race that opens the competition Tuesday.
"I don't think it's a great idea. There's a chance for injury," added Fabian, who was among several coaches who expressed concern during a pre-race meeting Monday.
However, swimming governing body FINA and local organizers said it wouldn't be a problem.
"They're pretty confident in the course design," Fabian said. "But you're really going to have to get into good position for that first turn. It's going to be like a bunch of horses, and nobody wants to see one of their horses get hurt."
Keri-Anne Payne of Britain won at the last full worlds in Rome two years ago, while Italians Martina Grimaldi and Giorgia Consiglio placed 1-2 at the open water worlds last year in Lac Saint-Jean, Quebec.
Angela Maurer of Germany and Poliana Okimoto of Brazil are also challengers, while the United States will be represented by Christine Jennings.
The top 10 finishers in the 10K events will qualify for next year's London Olympics, where the only open water races will be the 10Ks.
"There's probably about 16 people that could be in the top 10, if not more," Fabian said.
The men's 10-kilometer event is Wednesday, with 2009 winner Thomas Lurz of Germany and 2010 champion Valerio Cleri of Italy among the favorites.
Racing continues in Jinshan with a 5-kilometer team event Thursday, men's and women's 5K races Friday and the marathon 25-kilometer events Saturday.
Start times for the 25-kilometer races have been moved an hour earlier to 7 a.m. for men and 7:15 a.m. for women to avoid warmer conditions in the afternoon.
Many competitors will try to recover in time for some of the pool events next week, namely the 1,500-meter freestyle.
Information from The Associated Press was used in this report.