I arrived in Koh Tao with the aim to finally get certified in Diving. Upon arrival in Koh Tao you will see that there are many choices of schools available for learning to dive. I decided to go with Big Blue as they are the longest running diving organisation on the island and I figured that if they had lasted that long then they must be good.
They were indeed very good and all went well :) 3 days later and after a lot of fun dives, exercises and the exam I was certified :) The Instructor was great and really made me feel at ease. If I go back to Koh Tao I think I will take the advanced courses there. Also, Koh Tao is a beautiful place to get certified, the clear waters, sea life, and island itself is very much a great place for diving.
I recommend them 100%.