competitors battling against the heat more than each other as a veritable heat wave descended on the fleet yesterday.

High temperatures combined with increased humidity and light air threatened to suffocate competitors, many of whom struggled around the race course while others simply sat on the shoreline.

The boardsailors never even made it to sea as winds failed to reach desirable levels.

Of those seeing action, both the Laser and Laser II classes -- boys and girls -- each managed to complete two races, although the races were of marathon duration, testing both patience and endurance.

Suffering under the conditions yesterday was Great Britain's Ben Ainslie, who entered the day leading the boys single-handed Laser class after five races but left in third place, trailing new leader Philip Buchert of Germany by seven points.

Ainslie, winner of the silver medal a year ago, won the first four races but faltered on Wednesday and again yesterday with a 17th place finish, although he did fight back to finish second in the second race.

Currently in second place overall is Lima Gustavo of Portugal.

Similarly, among the girls German Petra Niemann was taken out of the top spot by Aussie Sarah Blanck, who recorded two firsts compared to a ninth and 13th for Niemann, now tied for second with Kiri Wong of New Zealand.

Extending their position at the head of the boys double-handed Laser II class were Nicholas Rogers and Pom Green of Great Britain after third and first place finishes that moved them eight points in front of reigning champ American David Ames and his crew PJ Buhler and a further nine ahead of Etiene Huter and crew.

Dutch duo Barbara Snieders and Wynkhe Bodewes have a healthy advantage in the girls double-handed Laser II, as they lead two time gold medallist Sally Cuthbert and sister Jessie of the UK.

Meanwhile, Bermuda's single-handed Laser competitor Megan Spurling is in 18th position, while male counterpart Jesse DeCouto, after a solid start to the regatta, has plummeted to 30th. In the double-handed Laser II Duncan Simons and Kevin Zuill remain 20th, while Nicki Crane and Charlotte Watlington likewise failed to move up yesterday and stay in 13th.

Today is a lay day.

LISTING SHIP -- Spain's Gustavo Del Castillo, holding the tiller, and his crew attempt to right their Laser II craft as they chase Russian Rodionov during action in yesterday's Nautica World Youth Sailing Championships.