You are docked in Old town in San Juan and in town at St, John, Antigua. ( I hope you are aware that you are not going to the island of St. John. ) St. Croix and St. Kitts are a fairly long, but not half mile, walk along a pier to the port shops. At St. Martin, Phillipsburg, you can easily walk to the port shopping area, but it is a hike to town. I suggest walking thru' the port area to the water taxi and take that into Phillipsburg. It is about a 10 minute ride and they run back and forth all day. The water there is incredibly beautiful. I love taking the water taxi. There is very little to see or do at the port area on St. Croix. I suggest an island tour. There are van taxis at the end of the pier that do the island tour.