There's no airport on Turtle Island — and that's the charm. Sleep south on the train, catch the dawn catamaran, dive by lunchtime.
Find a room before you go.
The route everyone ends up loving: evening sleeper from Krung Thep Aphiwat, arrive Chumphon before dawn, transfer to the pier and ride the first catamaran out — you're on Sairee Beach before your Bangkok hotel would have served breakfast. Book it as one combined ticket.

Affiliate link. If you book through it we earn a commission, at no extra cost to you.
Second-class sleepers to Chumphon connect with Lomprayah's dawn catamaran. The combined ticket includes the pier transfer and holds the boat if the train is late.
VIP coaches leave Bangkok's Khao San area each evening, timed for the same morning boats — often the cheapest joined-up ticket.
A slow boat with mattresses on deck leaves Chumphon near midnight and reaches Koh Tao at first light. Basic, memorable, and the fallback when everything else is full.
Step-by-step transport guides for this stretch of the Gulf coast.