Getting around on Ko Samet: The island has only a single main road. Some parts are concrete and some parts are only a dirt trail which get quite bumpy. There are two methods to get around the island. The first is by songthaew usually a rather well-worn pickup truck with two benches in the back and no roof, which costs 200 baht for a private trip, or between 20 and 60 baht per person for a full car, depending on which beach you are going to. This is a rather expensive method to get around the island, and the dusty roads can make it an uncomfortable trip. The second way is by renting a motorcycle for 300 baht/hr 500 baht/day or ATV 4 wheeled motorbikes for 500bht/1hr or 1200bht/day. You will usually be able to rent it from the hotel you are staying at. Leaving your passport or a deposit is not necessary or advisable.
Warning: It is advisable to hire motorbikes only from reputable hotels and lodgings. Stores renting out motorbikes or ATVs may attempt to overcharge you for repairs and labor should you damage the bike, even superficially. Initial quotes for repairs is often exorbitant and is way beyond the price of labor, parts, and repair.
A basic map of Ko Samet is available here. (http://www.maps-thailand....)
