Rio de Janeiro (AFP) - The world's best racing sailors dueled each other, tricky winds, currents -- and floating garbage -- on Rio's iconic Guanabara Bay in a warmup Saturday for next year's Olympics.
The test regatta, which will run until August 22, features 339 sailors from 52 countries, in many cases the same athletes returning to Rio in 12 months to compete for medals.
Laser dinghies and windsurfers were among the first of the seven Olympic classes in action, their colorful sails standing out against the cliffs of Rio de Janeiro's Sugarloaf Mountain.
Sailing often feels left out at the Olympics, since the need for the right sea conditions can require races to be staged far from the host city or even in a different part of the country, as was the case for the 2012 London games.
This time, sailors get to compete in the spotlight -- and they're thrilled.
France's Jonathan Lobert, who won Bronze in 2012 in the Finn class, called Guanabara "the best stadium of the Olympic Games."
"It's very nice for the sport to be in the heart of the Olympic city, because sailing is usually a little bit away," he said.
Six courses are being tested, some in sheltered waters and some further out in the ocean, where the waves become a factor.
- 'Very complicated bay' -
In addition to the setting, sailors say they are excited by the peculiar natural challenges of Guanabara.
"It's a very complicated bay, with great variations in the current and wind," Brazilian sailor Fernanda Decnop said.
Although lifelong local knowledge is expected to be something of an advantage for native Brazilians, many international sailors have been training intensively in Rio to catch up.
"I think everyone will find the conditions pretty difficult," Decnop said.
A less welcome challenge facing sailors and windsurfers is the pollution in Rio, where huge quantities of untreated sewage go directly into the sea, posing potential health risks.
The most immediate danger, though, comes from floating household garbage.
"The bigger problem is hitting something," said Marina Lopez, a crewmember on a Spanish Nacra 17 catamaran.
"It's already happened that someone hit a plastic bag or something. You can't see it until you hit it."
In the narrow margins of Olympic-level racing, just snagging a bag on a boat's rudder can make a huge difference.
"You have to stop and clear the rudder," said Australian sailing team spokeswoman Cora Zillich.
"Or it could be something solid and you capsize."
Despite repeated assurances from Brazilian authorities that the bay is safe, International Sailing Federation head of events Alistair Fox said the sport's governing body is taking the problem seriously.
"We've specifically appointed a member of our medical mission, a trained doctor in tropical medicine, to be here," he told journalists Friday.
"The other area obviously we're very concerned about is objects in the water that could affect the fairness of racing."
However, many sailors appear to be relaxed about the dirty waters, saying that every location has its problems and that for them the only focus now is on the race for medals.
"In San Diego, when you sail, you get seaweed. In Newport, Rhode Island, it's grass, in Queensland, Australia, you're worried about box jelly fish," US coach Jay Glaser said as he helped sailors rig a catamaran.
"This is a great place to sail, super-scenic, really challenging."