KERI-Anne Payne notes the incredulous expression on my face as she explains that the water temperature in the icy depths of Loch Lomond in September is in fact comparable with that which she experienced off Copacabana beach 12 days ago. And, unlike the rogue quantities of raw sewage floating around off the coast from Rio, there is certainly no question about the water quality.

"Loch Lomond is beautiful and it is actually pretty warm," says the 28-year-old Olympic open water swimmer. "I have done these things all over the world and there is almost nowhere better than this water, it is so clear and so crisp, like drinking a bottle of spring water. The scenery is incredible and if the sun peaks out now and then it just makes it all the better."

Those famously bonnie banks will rarely have seemed bonnier than they will to the hardy band of competitors who emerge onto dry land after participating in this weekend's Great Scottish Swim. The event actually began yesterday afternoon when around 150 swimmers spent anything up to four hours in the Loch participating in the 10k marathon swim event, but the headline event takes place today, as Payne and Scottish Olympic swimmers Robbie Renwick and Craig Benson participate in the elite event over one mile, while a cast of eager amateurs, including TV star Ferne McCann, formerly of TOWIE and I'm a Celebrity, take the plunge behind them.

The event is now in its fourth year at this picturesque venue and this will be serious business for Payne, even if not quite such a desperate scramble as the marathon swimming event in Rio, where four years of build-up for a podium place ended up with Payne back in seventh. The 28-year-old, who was born in Johannesburg, is an adopted Scot as she lives in Portobello with her husband and former Scottish swimming star David Carry.

"I must admit that I haven't actually swam since my 10k," she said. "I am always desperate to win, although there won't be any scratching, biting and pulling each other's legs going on. I haven't actually won here, although I did win the race when it was at Strathclyde Park. But I am only 12 days out from my Olympic race, which I put every part of my self into. Everything that I had left is all still out there on the Copacabana."

The intervening days have diluted Payne's disappointment about her Rio finish. Conditions in the water on the day didn't suit her, while there was pride simply to be derived from being part of a combined Team GB effort which surpassed even the London medal target. She was particularly thrilled to watch her friends Alistair and Jonny Brownlee finish first and second in the triathlon.

"I feel a mixture of disappointment and pride," she said. "I am incredibly proud of the achievement because it was my third Olympic games and I went in totally as the underdog. In terms of the result itself, it wasn't quite what I was hoping for - because I had put everything into a podium finish - but the conditions on the day just weren't right for me. They were really flat and really calm, while I would have preferred it really wavy."

Payne has yet to commit to participating in Tokyo in 2020 though much water will pass beneath the bridge before then. She has plenty to be getting on with besides. She and Carry have a nascent business called Triscape to build up - it offers elite retreats, with sports science, health and nutritional advice to aspiring athletes - while Payne also plans to offer nutritional recipes on a YouTube channel.

"If you pressed me right now I would say I have had 12 days off and I have quite enjoyed it," she said. "It is so hard when you come back from such a major meet. I have given everything in the last four years, sacrificed a huge amount. I finally got to meet my newborn nephew who is 25 days old the other thing. That is the kind of thing I have to put first - my family, life and business. But I will get to a point I am sure why I say 'right, I miss it'."

Benson is another Team GB star hoping to make a splash after Rio disappointment, even if open water swimming for him is merely a busman's holiday. The 22-year-old pipped his University of Stirling stablemate Ross Murdoch for a Team GB place in the 200m breaststroke, but failed to make it out of his semi-final. Instead, it was another member of the Stirling group, Duncan Scott, who stole the show, returning with two silver medals.

"I am on time off from my actual training, this is just fun for me!" he said. "I did it two years ago, and I was a little bit apprehensive because I was going from 100m or 200m breaststroke to a mile in freezing cold water swimming freestyle but I absolutely loved it. I guess it is a bit like going from running on a treadmill to going for a run on the roads.

"It did take me a few days to get over Rio but I still feel I took a lot out of the experience," he added. "I learned a lot from other athletes and actually feel more motivated than I ever have been in my career, to push on for Tokyo already."