The polluted Olympic waters caused no ill effects on the opening day of the Rio 2016 sailing regatta, with Norfolk-born windsurfer Nick Dempsey saying the conditions were the 'best it has ever been'.

Build up to the 11-day competition has largely revolved around concerns over water quality, with bacteria potentially putting athletes' health at risk and rubbish affecting their medal chances.

London 2012 silver medallist Dempsey, who has spent large patches of recent years in Rio de Janeiro preparing, was quick to praise the water quality.

'It was brilliant today – today it was the best it has ever been,' the early men's RS:X leader, who won his first two races, and came second in the third.

'You're always really nervous when you're winning a race and you're going fast.

'You think 'okay, the only thing that can go wrong now is if I get something stuck on my fin'.

'I was constantly worrying about it today but I didn't hit anything at all, so that's really good for me today.

'The last week has been pretty good. So far, so good.'

Earlier in the day, Smythe-Davis had comfortably defeated Austria's Sabrina Filzmoser with a Yuko and Waza-ari in the last 32.