George, 8, Charlotte, 6, and Louis, 3, were all spotted sailing with their parents on a small boat on the north Norfolk coast in early August.
A source told Vanity Fair: “They are very much a family of sailors now.
“Kate has always been a competent sailor and William’s pretty good too.
“They have enjoyed some wonderful time on the coast this summer sailing and showing the children how to steer and sail a boat.”
They added that the three children also had a whale of a time swimming in the sea and were undaunted by the “fresh” waters.
“The kids were all running in and out of the water with their dog and spent hours playing in the sand,” the source continued.
This year the Cambridge family spent their summer holidays in the UK, due to the Covid pandemic.
They visited the Scilly Isles off the Cornish coast and spent some days with the Queen at Balmoral in Scotland.
As the summer comes to the end, Prince George and Princess Charlotte are preparing for a return to school.
Both attend Thomas’ School in Battersea – George is starting Year 4, while Charlotte will be in Year 2.
Prince Louis will continue to attend Willcocks Nursery School.
Source: EXPRESS CO UK