Not every great experience demands noise. Some of the highly memorable ones ask you to slow down, look around, and simply take in where you are. The Sisters' Serenity is a single-day sightseeing cruise that sails to one of Singapore's quietly stunning destinations, the Sisters' Islands, a pair of small, unhurried islands sitting in the southern waters of the country, largely untouched by the pace of the city that lies just beyond the horizon. Getting there by sea, watching the skyline gradually give way to open water and green shorelines, is half the experience.