Rio Olympics 2016: Nick Dempsey leads men's windsurfing at halfway

Nick Dempsey took silver in London four years ago having narrowly missed out on a medal in 2008

Nick Dempsey's lead was cut to just one point in the men's Olympic RS:X windsurfing on Tuesday, as Giles Scott got started in the men's Finn class.

Dempsey, 35, won his first race of the day but then finished fourth and 14th to allow defending champion Dorian van Rijsselberghe to close the gap.

However the 2012 silver medallist has won an appeal against the 14th place after being knocked into the water.

Scott, 29, sits 10th after two races, with Slovenia's Vasilij Zbogar first.

Although Dempsey said he was happy to be "leading from the front", his 14th place conceded some of the advantage he had gained from a blistering start that saw him win three of the first four races.

He entered the water following an altercation with Lithuania's Juozas Bernotas at the start of the day's sixth race.

The successful protest means the 14th place will be discounted and Dempsey will be awarded a score taken as the average of his first nine race finishes.

"When the wind does that, everything gets clustered and I thought they were going to call the race off," he said.

"I'm leading at the Olympics so I'm happy about that. It's good to race from the front."

Giles Scott has won the last three world championships in men's Finn class

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Other Britons in contention

Scott, a four-time world champion, missed out on competing at London 2012 to Sir Ben Ainslie despite winning his first world title in 2011.

He was caught out by changing winds in his opening race to finish 17th but recovered to finish third in the second race and be within striking distance of the leaders.

Nick Thompson finished ninth and 15th in his men's Laser races on Tuesday to move to 12th overall. Julio Alsogaray of Argentina leads.

Bryony Shaw is 10th after six races of the women's RS:X windsurfing, with Flavia Tartaglini of Italy leading the way.

Alison Young has 43 points after a 26th-placed finish in her fourth race in the women's Laser Radial, leaving her 36 points adrift of China's Xu Lijia.