The combination between the wonders of the underwater world surrounding Koh Samui and the aquatic freedom that snorkeling can grant is a powerful one. Simply gliding through the warm waters of the Gulf of Thailand, taking in the exotic marine life, is intoxicating, and many full-day and half-day tours offer the best of this magical world. Surrounding islands offer the chance of a lifetime to spot the wildlife below the waves and in gin-clear water.