We're often asked by people whether Thailand has good diving.
And there's always a moment of hesitation before saying
Our least controversial reason is simple: murkiness. Most of our experience with Thailand is in the Gulf, where there's more sediment than on the western, open-sea part of the country. But when diving basically anywhere along the coast, in our experience, visibility is fairly poor. In fact, the only non-murky places we've been to were generally far off-shore, such as in the Similan Islands.
The other reason is tourism. Thailand has a tourism industry thriving to the break-point, so unless you're willing to spend some considerable money (or, in our case, speak Thai), you'll probably be joined by a large group of divers. And your large group will be one of many. And those dive groups in general are populated by first-time divers.
We still love it, though—but as we've spent a lot of time living in Thailand, it's an easy place to love. Just not so much for diving!