You won't want to pass up the opportunity to go fishing in Koh Samui! The islands that are situated to the south of Koh Samui, like Koh Taen, Koh Rap, and Koh Mat Sum, are known for having some of the best fishing opportunities in this region. Since you get to enjoy the ride on a traditional wooden Thai boat that has a roof over it to protect you from the sunshine and the rainfall, you will find that it is a really soothing experience. Additionally, all of the required fishing gear will be given, so there is no need for you to carry anything with you. Many resorts the likes of Santiburi Koh Samui offer excursions like this as part of their vacation packages. It's best to check with the specific resort you are interested in to see what excursions they offer.