RIO 2016 opened with the worst Olympic conditions Berkshire rower Katherine Grainger has ever faced, with high winds and choppy waters leading a boat to capsize and athletes to air their frustrations.

Complicated preparations for the first-ever Games on South American soil have been focused largely on the threat of Zika and polluted water at the Rio venues, but it was natural conditions that was the main issue on the first day of rowing.

Several boats struggled to stay afloat and the Serbian men's pair of Milos Vasic and Nenad Bedik succumbed to the conditions, being dunked in the Lagoa during their heat.

The Executive Committee ruled the duo could continue in the next round of racing but it underlined issues facing rowers, with reigning champion Grainger from Maidenhead and women's double sculls partner Vicky Thornley taking to the water in the heat immediately following Serbia's mishap.

"We were sitting at the start and were delayed by 15 minutes already, then delayed again because they said there was a technical fault in the finish area," Grainger, competing at her fifth Olympics, said.

"We didn't know until afterwards that it was because someone had fallen in.

"We were aware from the warm-up how rough it was and how dangerous that is in those racing boats.

"But it is very, very much what we've talked about in practice - staying in the moment and the stroke you're on and not trying to predict what might happen further down the course.

"I don't know if it's the absolute worst but it's probably the worst Olympic conditions I've ever raced in.

"We knew that as beautiful as this course is, because it is open it means it is open to the conditions, so all of us knew coming into this event we could get anything.

"And even the week we've been here training it's changed moment to moment, day to day."

Reigning champion Grainger, who is GB's most successful female Olympic rower, and Vicky Thornley were pipped to victory in the heats of the women's double sculls heats, finishing 0.5 seconds behind the Lithuanian boat. However, they are safely through to the semi-finals.

Great Britain's coxless fours also qualified for the semi-finals on the first day of rowing competition. The quartet, who included stroke Peter Chambers and Jono Clegg, both from Maidenhead, finished second behind former world champions in the second heat.

However, the Berkshire trio of Jack Beaumont and Peter Lambert from Maidenhead, joined by Sam Townsend from Reading, could only finish fourth in the quadruple sculls. They will have a second chance of making next weekend’s finals in the repechage this weekend.