From Bangkok, the most common way to get to the island is by regular bus or minibus (plus ferry). The buses leaves from either Ekkamai (Bangkok's Eastern Bus Terminal), from Suvarnabhumi Airport or from Khao San Road (known "backpacker-street" in Bangkok). Tickets are available at the bus station or in virtually any travel agency in Bangkok. There are also mini van from the Victory Monument in Bangkok direct to Ban Pae pier,the price is only 160 baht per person(the price could be changed after sometimes).
The bus will take you to either Rayong, or directly to the ferry pier in the fishing village of Ban Phe. From Ban Phe there are direct boats to Koh Samet. If the ferry ticket isn't included in the price, you are able to purchase a ticket next to the pier. The boat fee costs 50 Baht for local people,and 100 baht per person for tourists from Baan Phe pier to Koh Samet. It takes about 15-40 minutes from Ban Phe to Koh samet,depends on what kind of the boats and the weather conditions.
The bus will take you to either Rayong, or directly to the ferry pier in the fishing village of Ban Phe. From Ban Phe there are direct boats to Koh Samet. If the ferry ticket isn't included in the price, you are able to purchase a ticket next to the pier. The boat fee costs 50 Baht for local people,and 100 baht per person for tourists from Baan Phe pier to Koh Samet. It takes about 15-40 minutes from Ban Phe to Koh samet,depends on what kind of the boats and the weather conditions.