Koh Tao used to be a place that people only ever visited if they wanted to come diving, also to get here it only used to be accessable by coming by boat from Surat Thani, Samui or Phangan, so it was a bit of a trek to get here. Now however with ferries also between Koh Tao and Chumphon, Tao is now either the first of the 3 islands here that people arrive at when travelling down from Bangkok or the last island they get the chance to see after visiting Samui or Phangan on their way back up to Bangkok.
Tao does have a lot of diving schools here and in addition to those many dive schools from Phangan and Samui come over to dive the same sites the dive schools here dive.
These days with the improved transport to the island and the convience of stopping over for a few days on the way up to Bangkok many people decend on the island the week following the monthly Full Moon parties over on Phangan and many of these people just come here to relax a little and recover from that party. Once they arrive on Koh Tao however they quickly realise that there's no need to stop the partying just yet as the Sairee Beach area especially is very lively with lots of bars and good restaurants to choose from, then for the real party animals down at the south end of Sairee Beach there are nightclubs which stay open until around 5 or 6am.
If partying and diving isn't your thing then relaxing on one of the beaches around the island with a good book is a very pleasant way to spend your time. If you're feeling a little more active there are a number of non diving related activities available on the island everything from a good old traditional Thai massage, mini golf to rock climbing and flying trapeze. So these days Koh Tao is definetly not just for the divers.
