Ferry to Ko Chang. The ferry service starts at 6:00 and goes till 18:30 or 19:00. Cars and motorcycles park on the lower deck, and passengers sit upstairs, where there’s a small cantine and a better view. On average, there’s 1 ferry an hour. You can get to the pier from a specific taxi station in town (50 Baht).
Note: they used to collect the tickets when you got on the ferry, but now the system has changed. There’s a booth at the beginning of the road to the pier, and they collect the tickets there. On the other direction, from Ko Chang to Trat, you have to keep your ticket until you leave the pier, the taxi then stops at the booth and you have to give your ticket there.