Sailing - Regatta sets sail on dirty water, tricky winds

By Jeb Blount RIO DE JANEIRO (Reuters) - Olympic sailing began an 11-day regatta on Monday with near perfect winds as competitors showed little fear of heading back into waters criticised for sewage-borne pathogens and floating garbage. Britain's Nick Dempsey scored victories in the first two races in the RS:X class on the Escola Naval course on Guanabara Bay. With winds blowing 10 to 11 knots and strengthening to 14 after the 1:05pm (16.05 GMT) start, Dempsey grabbed large early leads in both r