Two good roads to the island of full moons and empty bays — pick the northern catamaran hop or the southern ferry workhorse.
Find a room before you go.
Coming overland, the Chumphon sleeper-and-catamaran combo is the scenic island-hopper, calling at Koh Tao on the way. In a hurry, fly to Surat Thani and take the bus-ferry combo from Donsak — more departures, more seats, especially around the party dates.

Affiliate link. If you book through it we earn a commission, at no extra cost to you.
Overnight rail to Chumphon, then Lomprayah via Koh Tao to Thong Sala — about three hours on the water, and one of the Gulf's prettiest approaches.
Budget flight, then joined-up bus and ferry from Donsak. Around 5–6 hours from Bangkok take-off to the pier at Thong Sala.
Overnight VIP buses connect straight to the morning Surat Thani ferries. Slowest, cheapest, perfectly serviceable.
Step-by-step transport guides for this stretch of the Gulf coast.