expectation of repeat customer loyalty, and also to offer different levels of quality and service. For instance, Carnival Corporation & plc owns both Carnival Cruise Line, whose former image were vessels that had a reputation as "party ships" for younger travelers, but have become large, modern, yet still profitable, as well as Holland America Line and Cunard Line, whose ships cultivate an image of classic elegance. In 2004, Carnival had merged Cunard's headquarters with that of Princess Cruises in Santa Clarita, California so that administrative, financial and technology services could be combined, ending Cunard's history where it had operated as a standalone company (subsidiary) regardless of parent ownership. However, Cunard did regain some independence in 2009 when its headquarters were moved to Carnival House in Southampton. The common practice in the cruise industry in listing cruise ship transfers and orders is to list the smaller operating company, not the larger holding corporation, as the recipient cruise line of the sale, transfer, or new order. In other words, Carnival Cruise Line and Holland America Line, for example, are the cruise lines from this common industry practice point of view; whereas Carnival Corporation & plc and Royal Caribbean Group, for example, can be considered holding corporations of cruise lines. This industry practice of using the smaller operating company, not the larger holding corporation, is also followed in the list of cruise lines and in member-based reviews of cruise lines. Some cruise lines have specialties; for example, Saga Cruises only allows passengers over 50 years old aboard their ships, and Star Clippers and formerly Windjammer Barefoot Cruises and Windstar Cruises only operate tall ships. Regent Seven Seas Cruises operates medium-sized vessels—smaller than the "megaships" of Carnival and Royal Caribbean—designed such that virtually all of their suites are balconies. Several specialty lines offer "expedition cruising" or only operate small ships, visiting certain destinations such as the Arctic and Antarctica, or the Galápagos Islands. , which formerly operated as part of the United States Merchant Marine during World War II before being converted to a museum ship, still gets underway several times a year for six-hour "Living History Cruises" that take the ship through Baltimore Harbor, down the Patapsco River, and into the Chesapeake Bay, and she is also the largest cruise ship operating under the American flag on the United States East Coast. Currently the three largest cruise line holding companies and operators in