Kate Tosses William a Splashy 30th Birthday Weekend
06/25/2012 AT 10:35 AM EDT
In a weekend party of fun and games organized by wife Kate, the prince, whose 30th birthday was actually June 21, was joined by brother Prince Harry and some his closest friends.
Activities included an excursion into the choppy seas off Anglesey, north Wales, where William was pulled across the chilly waters on an inflatable rubber ring by a speedboat – leaving locals abuzz when news of it was leaked to the Sun tabloid Monday.
Some of William's oldest and closest friends, including Thomas van Straubenzee and Harry Aubrey-Fletcher, were on the island to help celebrate, just as Kate's sister Pippa Middleton was also believed to be there for the party.
Despite the calendar saying it is summer, the weather was rainy and windy, but a source told the Sun that the foul weather didn't inhibit the festivities.
"For most 30-year-olds," said the source, "the last thing they would want to do is freeze themselves on a wet weekend in Wales. But this is typical of William."
The group then headed to the couple's rented farmhouse for a birthday dinner.
The couple spent much of last week based at Prince Charles's country home Highgrove house, Tetbury, Gloucestershire, so William could take his RAF helicopter course nearby. On Wednesday, Kate was spotted shopping in the local village.
William, who upon turning 30 inherited $16 million from his late mother Princess Diana, is reported to have received a specially-designed watch from Kate for his birthday.
It is also said that he may have been given the portrait of Kate by the artist Nicky Philipps that was commissioned by Prince Charles.