Diamond Princess is a British-registered cruise ship owned and operated by Princess Cruises. She began operation in March 2004 and primarily cruises in Asia during the northern hemisphere summer and Australia during the southern hemisphere summer. She is a subclassed ship, which is also known as a "Gem"-class ship. "Diamond Princess" and her sister ship, , are the widest subclass of "Grand"-class ships, as they have a beam, while all other "Grand"-class ships have a beam of . "Diamond Princess" and "Sapphire Princess" were both built in Nagasaki, Japan, by Mitsubishi Industries.