Destinations in Thailand:
(The Seatran Discovery ferry at the Bangrak pier on Koh Samui)
The Seatran Discovery uses the Bangrak Tourism Port at Big Buddha Beach on Koh Samui which is next to the Koh Samui Airport making it a popular connection for people who fly to Koh Samui and want to transfer to Koh Phangan.
(The Seatran Discovery time tables and prices, March 2012)
Tickets for the ferry between Koh Tao and Koh Phangan cost 400 baht, between Koh Tao to Koh Samui 600 baht and between Koh Phangan and Koh Samui 250 baht. For actual prices and time tables it is best to check the website of Seatran Discovery.
Website: Seatran Discovery