We originally were planning to scuba dive. But after Nepal, our body was so beaten up we didn't think it was worth it since it takes 4 days to get certified.
So, snorkelling seemed like a better fit for us. There are tons of tourist agencies offering scuba diving. They're all more or less the same. It's a full day trip for 750 baht which includes transportation, snorkelling gear, lunch, fresh fruits and drinks (water, coffee tea). The tour takes you around the island to Shark Bay, Aow Leuk, Hin Wong Bay and Mango Bay. They also take you to Nangyuan Island, but you'll need to pay a 100 baht entrance fee.
That seems like a pretty good deal right?
Our Experiences
Let me preface this by saying that you get what you pay for. It's alright, since it's only 750 baht + 100 baht entrance fee.
You only get about 30 minutes at each stop, which isn't too much time to actually see much, since you'll need to swim to the area and back. Since we were running behind, we missed out on Aoe Leuk and went straight to Hin Wong Bay.
Shark Bay
This is supposedly the best spot to see sharks. Not the big scary ones, but the smaller ones. Unfortunately, we didn't see any nor many other fish. The water was choppier than expected, so it was hard to swim out and back in time.
Hin Wong Bay and Mango Bay
These ones were a bit better. If you swim out closer to the rocks, you'll see more coral in that area. Granted, most of the coral is dead, so you won't see much. But there are still some fish searching around for food.
When you swim back to the boat, you'll noticed a lot more fish. I realized that the guides will feed the fish so you'll see them. We ended up having lunch at Hin Wong Bay. It's just a container of rice, a fried egg and basil beef which isn't bad.
Nangyuan Island
Nangyuan Island is popular small island off the coast of Koh Tao. It's makes an excellent day trip with its stunning views. Since it was part of our snorkelling tour, we didn't bother with trying to visit it.
If you paid the 100 baht entrance fee, the tour will drop you off here for about 2 hours. Since we skipped one of the bays, we ended up spending 2.5 hours here, which is more than enough time.
The beach here is quite unique, since you have water on both sides. It's a good place to lounge on the beach and catch some sun. However, I found the sand a little too coarse because of the coral, so I wouldn't recommend visiting if you were just swimming.
I enjoyed snorkelling here to the most. We found a spot by the rocks closer on the opposite side of the dock that has a lot of fish. Since the water is shallow, you can actually see a lot more that goes on.
Things to keep in mind
Make sure you get a good set of snorkelling gear. Mine was leaking, so I had to switch it up after the first stop.