The Duke and Duchess of Cambridge have raced each other on yachts on the fifth day of their tour of New Zealand.
They joined the crews of America's Cup yachts for two races in Waitemata harbour off the coast of Auckland.
Earlier, the royal couple visited an air force base, sharing parenting tips with serving airmen and women.
Prince William joked that his eight-month-old son, Prince George, had already received a string of marriage offers in New Zealand.
On Wednesday, Prince George attended his first official public engagement at a "crawl-about" with babies of similar age at Government House in Wellington.
He will not be making any more appearances during his parents' 19-day tour of New Zealand and Australia, but has continued to be a focus of attention.
Prince William and Catherine took part in two yacht races on Friday, being pitted against each other on America's Cup class 80ft sloops.
Catherine joked with her husband before the start, warning William to "take care" as they set off.
He replied: "Yeah, see you later."
Catherine was joined by Dean Barker, Team New Zealand captain and a crew member of his nation's 2000 America's Cup team.
Their team won both races.
Prince William was paired with veteran yacht racer and Team New Zealand manager, Grant Dalton.
During their visit to the harbour, a small plane flew overhead trailing a protest banner.
It read: "Time for a Kiwi head of state."
Earlier, on a visit to a Royal New Zealand Air Force base, William met new parents Karen and Jason Dreaver.
Their daughter, Emily, was born just nine days after George in July last year.
Mrs Deaver, 40, said: "We mentioned how well-paired she and George would be in the future."
"William said, 'There have been a few babies touted to us' - he could see the funny side."
William also discussed parenting with other couples - reassuring one young couple that things get easier as the months go by.
Catherine discussed the challenges of being a young mother and maternity leave.
Melissa Tilbury, 28, was with her five-month-old daughter Madeleine.
Mrs Tilbury said: "She said when George was much younger William was away a lot in the beginning - but that you get by."
She added that Catherine was "really good" with her daughter.