Prince Charles has advised Australian Olympic open water swimmers Melissa Gorman and Ky Hurst they'll need some antiseptic after they compete in the Serpentine.
The 11 hectare lake in Hyde Park has been cleaned up for the 10km open water swim at the London Olympics, but its reputation obviously still lingers in royal circles.
"Even he admitted we should gargle some antiseptic when we get out of there," Gorman said.
But Gorman was comfortable swimming in the 200-year-old lake on August 9.
"It's definitely clean enough. We swim in all sorts of water in open water, it's a different experience."
Gorman and Hurst were among several Australian athletes to meet Charles and his wife Camilla at the start of the men's cycling road race on Saturday on the Mall, the road which runs along the fence of the prince's backyard to his mother's home at Buckingham Palace.
For teenage archer Elisa Barnard, it was yet another pinch yourself moment at her first Olympics after the thrill of preparing to compete at Lord's and Friday night's opening ceremony.
"This whole Olympics is just a once in a lifetime opportunity," she said.
"When they asked me yesterday and said I'd been selected to see them, my jaw just dropped to the ground.
"I said `why me, I'm just little old me from Sydney, I don't deserve to meet the royals.'"
After the queen's starring role in Friday night's opening ceremony, the royals are obviously keen to enjoy their Olympic experience.
Trampolinist Blake Gaudry said he had some general chit-chat with the prince about sport and life in the athletes village.
"It's so strange just to have such a simple conversation with the royal family," he said.