Koh Samui Transport
Samui is extremely easy to get around. In fact, a round trip by car can be done in about an hour. Of course, it makes much more sense to take a little longer and see some of the sights along the way. The ubiquitous songthaews (pick up trucks) are the normal mode of public transportation although there are also conventional taxis. Many tourists however choose to hire a motorcycle or car.
Taxis
Samui has many yellow metered taxis for those who prefer to travel in air-conditioned comfort. They can be found at the airport and cruising the islands major roads throughout the day and night. The downside is that it can be difficult to get drivers to actually turn on their meters and prices can be high, so try to negotiate a reasonable fare before departing.
Covered red pick-up trucks called songthaews are effectively the local taxi/bus. The destination of the songthaew is clearly marked on the front and sides of the vehicle. They follow fixed routes around the island, but there are no official stops. They are simply flagged down when wanted. To get off, just press the button for the bell and then pay the driver. At night, fares can be higher. It is also possible to charter a songthaew as a taxi, but this costs more.
By car
Renting your own vehicle is an excellent way to get around as it allows you to explore the many small roads and tracks that lead off into the jungle-clad interior or down to one of the islands many little coves and deserted beaches. Local operators generally rent manual shift Suzuki jeeps, while the major car rental companies like Avis and Budget now rent both manual and automatic air-conditioned cars and jeeps. Smaller companies will ask you to leave your passport as collateral on the vehicle.
Make sure that full insurance is included or you will be held responsible for the potentially ruinous expense of any damage to the car in an accident and compensation for others involved. Hiring a car may be more expensive than a motorcycle, but it is a lot safer. It is also possible to hire a car and driver for a reasonable price by western standards, and this removes the worry over insurance.
Many visitors to Koh Samui rent 100cc four-gear Honda Dream's and Wave's for reasonable local prices. Be careful that you don't get a 'Samui tattoo' a burn on your right calf from the exhaust when changing gear. Fully automatic Yamaha Neuvo's are slightly more expensive, but are much easier to drive.
A word of warning should be given though: Koh Samui has the highest rate of driving fatalities in the kingdom, and motorcyclists are much more vulnerable than other road users. Stay sober and be especially careful of sand on the road. Motorbikes do not come insured, so you will be responsible for anything that happens in an accident.
Tourist services
There are a myriad of tourist agencies on the island that offer sightseeing tours to all the main attractions as well as bus, train, boat and air travel all across Thailand and the world. Some companies will tailor their sightseeing trips to fit the wants of visitors.
Some hotels also offer these services, but their tours tend to be slightly more expensive. When booking a tour with a travel agency or through a hotel, it may be worth checking with another operator to compare prices. Although prices rarely differ by huge amounts, this will give you a clearer indication as to the genuine price of things.
From the airport
It is advisable to take a taxi from the airport, unless being picked up by a hotel van or car. There are a number of independent drivers who will take you wherever you wish to go for a negotiated price, and there is also a limousine service available from the airport.
Samuis roads are pretty scary affairs, with numerous accidents involving foreigners happening each year. Whether it is in a taxi from the airport, or when you are driving alone, ensure that you buckle-up and take care.
It is possible to rent a car at the airport from one of the main car hire operators, and given the short distance between the airport and anywhere else on the island, this tends to be conveneint. If it is your desire to rent a car in town, wait until you get to your hotel, where there will be a rental service nearby.
Similar guides available in Thailand include
Getting around in Bangkok
Getting around in Chiang Mai
Getting around in Pattaya
Getting around in Phuket