HAMBURG, GERMANY - JULY 21:  Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge arrive for a visit of the Maritime Museum on the third and final day of their visit to Germany on July 21, 2017 in Hamburg, Germany. The Duke and Duchess of Cambridge will celebrate the joint UK-German year of science which for 2017 is focused on oceans.  (Photo by Alexander Koerner/Getty Images)