The royal siblings were spotted on another yacht with their grandparents, Michael, 70, and Carole Middleton, 64.
George, 6, wore a captain’s hat and a life jacket over his navy-and-white striped polo top, as he watched the boat race.
He flashed a toothless smile as his parents went head to head alongside celebrities to raise awareness and funds for eight of their patronages.
Princess Charlotte, 4, could be seen sitting inside the boat, wearing what looked to be a blue dress with a white Peter Pan collar.
According to reports, Kate and William’s youngest child, 1-year-old Prince Louis, was also in the area on the day.
Prince George celebrated his birthday last month before heading off on holiday with his parents and younger siblings. Photos of him were released to mark the occasion.
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