Silver Shadow of Silversea Cruises will call at the Japanese island of Okinawa 10 times in May, a local media report said. The ship will be based in Shenzen in China on the cruises that will include calls at Hirara, Naha, Ishigaki and Nakagusuku. It has called on Okinawa before, but ths is the first time it will do this from a base port in China. The ship is scheduled to make four cruises from there with calls at Okinawa, the report on ryukyushimpo.jp said.