For the first time, veteran sailor Thomas Wong Kam-chuen and his partners set sail from Hong Kong on their 46-foot yacht on a two-day trip earlier this month to a holiday island in Zhuhai, testing the waters for more leisure travel to mainland China. After a five-hour voyage from the Causeway Bay typhoon shelter on a sunny weekend, they anchored their Danish-built yacht, DBX2, at Guishan Island, went ashore for a seafood lunch with beer and stayed overnight. “Food is really economical. We had 11...