In the beginning of the 90's, transportation was still pretty basic, with buffalo carts & boats being used to getting around. The first diving excursions came from Samui, staying overnight in simple huts without electricity.
But soon, a couple of very basic dive centers started operating on Koh Tao. Equipment was limited, wetsuits were not available for customers and only small fishing boats could be used to take divers to the sites.
Finding popular sites was a combination of lining up fix points on the horizon and dragging dive masters on ropes behind the boat, hoping they would recognize the sites from the surface.
Since this time Koh Tao has exploded on the diving circuit and it now has the reputation of being the main training center for dive students in South East Asia.
International diving agencies are represented on this small island: SSI, PADI, BSAC and CMAS. So greatly has the market growth been that PADI & SSI have established their representatives on Koh Tao to monitor the quality and to keep their members up to date.
All course levels are available, from beginner to professional, including specialities like UW-videography and nitrox diving, so if you just fancy a few days of fun diving or wish to go on with your underwater career, it's all here.
Actually Koh Tao has become the leading area in Thailand for Instructor Development Centers (IDC). IDC courses are held monthly.
Up-to-date retail shops offer quality brand scuba gear (Scubapro / Suunto / TechniSub / Mares / Seac Sub / Isaw / Feelfree / GoPro etc) for very attractive prices.
Own equipment can also be serviced or repaired.
Safety is at a high level with a DMT O2 & evacuation station located on Koh Tao and a big compression chamber on Samui only 90 minutes away by speedboat.
Most of the reputable shops have staff that are fully trained first aiders and provide oxygen on the boats and in their facililities, they also offer diving insurances, to give that extra bit of peace of mind.
If you don't fancy diving (yet), you can join always join the dive trips as a snorkeller or just enjoy the scenery.