Koh Tao is reached by ferry or speedboat from Koh Samui, Koh Phangan, and the mainland port of Chumphon. From Bangkok, the most common approach is the train or bus to Chumphon followed by the overnight ferry — the night boat departs Chumphon around midnight and arrives at Koh Tao around 6am. Lomprayah and Seatran are the main speedboat operators and run daytime services from both Chumphon and the Samui/Phangan cluster.
From Chumphon, the journey takes about 2 hours by high-speed catamaran or 6 hours by slow overnight ferry. From Koh Phangan, it is about 1.5 hours. Ferries dock at Mae Haad pier on the west coast.