Are we talking of the Koh Tao near Samui

Went there a good few years ago so any info I've got may be out of date. Stayed in Koh Tao cottages for a night...pretty basic, good food in restaurant. There were a lot of snorkelling/diving sites around the island. Also close to Koh Tao (few minutes by boat) is the dive resort island of Koh Nang Yuan...great snorkelling there...basically three rocky islets joined by sand bars...one of the more amazing places I have been too in Thailand..caters to day trippers as well as people who want to stay.