I got my Advanced Certification here, and felt that the staff truly cared about making sure we were well-trained and knew what we were doing. I am confident in the skills that I learned. While we were there, we went on a number of dives with a variety of different guides with unique styles. I appreciated the briefings before each dive. The week we were there, the weather was unusually windy, so the visibility was very poor. The rides to the dive sites were treacherous at times, but it was an adventure. I loved the dive boats. The equipment was in good shape. I would recommend Big Blue to anyone looking to take a diving course or to get in a couple fun dives while on Koh Tao.