Prince William and his wife, Kate Middleton, boarded the royal yacht Britannia, which was docked in Edinburgh, this afternoon in order to celebrate his first cousin Zara Phillips's wedding with a cocktail party! Kate recycled the green Diane von Furstenberg dress she wore during her visit to LA earlier this month. Prince Harry was also in attendance, and he was spotted ascending the same carpeted stairs that the bride and her husband-to-be, Mike Tindall, walked up. Zara was decked out in a dress from Alice and Olivia. Princesses Beatrice and Eugenie also colorfully turned out, along with the elder's boyfriend, Dave Clark. Zara Phillips and Mike Tindall will marry tomorrow at the city's Canongate Kirk, and her royal relatives will be out in full force. Kate and William often go by their titles of the Duke and Duchess of Cambridge, but their Scottish equivalents are the Earl and Countess of Strathearn. Scotland is a special place for the couple, as it's where they met and fell in love while students at the University of St. Andrews. Wales, though, has been their home as of late, as it's where William works with the Royal Air Force when not traveling with Kate for family obligations.