Taking your motorbike to Ko Chang Island in Trat Province is possible and easy.
Koh Chang Ferry (Aow Thammachat) ท่าเรือเกาะช้างอ่าวธรรมชาติ is the place to go to embark your motorbike and yourself.
There’s a ferry every 20 min every day from the pier
It cost ฿ 150 for a single trip including your motorbike.
The Ferry is medium size, so during high season I will recommend booking your ticket if you want to arrive on time (though I doubt that you cannot find a place with a ferry every 20 min)
Unlike the ferry to Koh Samui, this ferry doesn’t have an area with air-con but you can survive 20 mm without right?
Onboard there’s a small grocery and coffee shop.
The arrival Pier
You will arrive at Ferry Centre Point Pier Koh Chang
In case you don’t have your own motorbike you can rent one right at the pier on your arrival.