Take the public ferry to Anguilla, dock in the middle of Gustavia in St Barth, or follow the longer route through Saba and Statia to St Kitts and Nevis. Here’s where to board and which islands are worth an overnight. The boat to Anguilla leaves from a terminal beside the market in Marigot. Twenty minutes later, you’re at Blowing Point, where you can get a taxi to Shoal Bay East and spend the day on one of the Caribbean’s great white-sand beaches. On the other side of St Maarten, a ferry leaves Philipsburg for Saba, where the road from the dock climbs toward red-roofed villages and the cloud...