PORTSMOUTH, UNITED KINGDOM - JULY 26: (EMBARGOED FOR PUBLICATION IN UK NEWSPAPERS UNTIL 48 HOURS AFTER CREATE DATE AND TIME) Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge visit the Portsmouth Historical Dockyard as they attend the America's Cup World Series event on July 26, 2015 in Portsmouth, England. (Photo by Max Mumby/Indigo/Getty Images)