Looking at the water, the palms, and the plants, you might think the color green was invented on Koh Samui, and then reinvented. Everywhere you look are shades of celadon, smaragdine, and viridian. Located in the Gulf of Thailand about 400 miles south of Bangkok, Koh Samui is an island of towering coconut trees, generous sun, and powdery white beaches. Cruise visitors will enjoy the Big Buddha, an important symbol for the locals, the Na Muang waterfall, and the beaches. Chaweng is the island’s high-energy beach. Lamai is less busy. Maenam is quiet, and closest to port.