Koh Chang is the largest of the many island in Trat Province. Trat is located in the southeastern corner of Thailand and shares a long border on the east with Cambodia and along the Gulf of Thailand on the west.
The most economical way to get there are several bus lines departing from the Ekamai Bus Terminal (aka The Eastern Bus terminal in Bangkok). The best is the 999 Government operated bus service that departs at 7:45 am and 9:45 am. The trip will take about 5½
The 999 is a first class bus with a/c…not one of the VIP buses with bar and karaoke that Thailand is famous for but non-the-less comfortable and at a cost of well under $10 USD each way; it’s a bargain. A small snack is provided by the bus line but you might want to bring some additional snacks and beverages along.
The bus will drop you at a staging point for getting to one of the two ferry piers to Koh Chang that runs every hour. Ferries to other islands also depart from the same piers. The first time you go through this process it will seem confusing and a bit chaotic but the people operating the service are very friendly (and used to dealing with tourists) so just ask for help if you have any questions and they’ll make sure you make the right ferry.
Once you board the ferry; it’s a 30-40 minute trip across the strait to the island. There are 2 ferry lines each with their own piers operating between the mainland and Koh Chang. Vehicles are packed onto the first deck and passengers are seated one level up on both lines. Just be sure to work out the details with your hotel as to which is the better for you to take.
As another ground alternative to the bus; hiring a cab or van for the drive there will cost more than the bus but less than a flight and you’ll have the advantage of being on your own schedule.
There is also a small but very comfortable and well maintained airport in Trat City that offers 3 non-stop45-minute flights per day to Bangkok Suvarnabhumi Airport (BKK) via Bangkok Airlines. We were a bit shocked to see some remarkably good freshly made snacks and water available to ALL passengers in the open air boarding gate prior to the flight.
When we visited Koh Chang we took the bus on our way there but flew on our return to Bangkok. We took advantage of a van service offered on Koh Chang with pick up at our hotel for the ride to the ferry where we move to the passenger seated area but upon arrival on the mainland returned to the same van for the 20 minutes drive to the airport.