Similan Islands
I went on a group trip to the Similan and Surin Islands in February of 2017 on the Junk liveaboard. The trip was a really great price, the dive liveaboard was clean and met basic necessity, and the food and the crew were really great. Overall, I would say that the wildlife in Thailand is very plentiful, although I would not say any of the dive sites particularly blew me away compared to other destinations except for a few: Richelieu Rock, Koh Bon, Hin Daeng, and Hin Muang.
Many of the sites on the Andaman side of Thailand had very interesting underwater structure -- huge boulder reef structures spotted with cup corals -- that were very unique to the dive destination, but not necessarily worth the price of the trip alone. However, the 4 dive sites I listed above were absolutely amazing, and these 4 dive sites alone made the entire trip to Thailand worth it, despite some of the other sites being slightly lackluster.
The pinnacles were covered in abundant soft corals that housed numerous nudibranchs playing hide and seek (spotting nudibranchs is one of my favorite scuba diving activities), surrounded by large schools of fish (both over the reef and in the blue), and sheltering abundant seahorses and cephalopods! I could've stayed on those locations to dive for all 10 days, they were so full of life and so vibrant and colorful.
To top it off, I stayed in Thailand for a few extra days to explore the area on land, and spent a few days traveling in Cambodia, as well. The region is so rich with culture and history -- combining these land activities with the beautiful diving made for one of the best trips for the price that I've taken! Don't forget to travel with your best dive buddies to make the trip irresistible:)
