If you are planning, or have already booked, a trip to Koh Samui, you probably should check the best things to do in Koh Samui in advance.
Above all, the extensive range of exclusive activities will definitely make your stay in Koh Samui unique.
In Koh Samui you can have extraordinary experiences that you will look back on for a long time. It is most recommended booking those activities in advance, if you do so you are guaranteed to get a ticket plus you will have more free time on your vacation :)