All of the 3 main Gulf-Coast Islands have been on travelers list for a long time and therefor are all very good developed. While Ko Samui is a touristic Hot-Spot with big range of available resorts, Ko Pha-Ngan with it´s famous Full-Moon-Partys is popular among Backpackers and individual travelers. Ko Tao is also rather a backpackers-place and furthermore widely known to be the place for Diving and Snorkeling in Thailand. Something that definitely shouldn’t be missed is a trip to the beautiful and well protected archipelago of the Ang Thong Marine National Park. The islands are all well connected to the mainland, with many ferries coming and going all day long. In addition its pretty cheap and easy to hop from one island to another. But before deciding to go there, keep in mind that due to it´s location the Rainy Season time differs in compare to other Thai Islands. The Monsoon-time here lasts from November into January.