Where to go for snorkeling to see Shark Bay and Turtle Island

Oxygen is widely regarded as the best operator on the island. For NYE, their "Premium Trip" is the ultimate chill option. Unlike crowded boats, this trip limits passengers (max 20-25) and focuses on a relaxed pace. They are famous for their excellent guides who actually get in the water to point out the Blacktip Reef Sharks at Shark Bay and the huge Green Turtles at Aow Leuk. They prohibit single-use plastic and serve a delicious lunch onboard.

If you want to avoid people entirely on New Year's Eve, hire a Private Longtail Boat. This is the most flexible option. You can tell the captain, "Take me to Shark Bay and Turtle Island, but avoid the crowds." You can bring your own cooler of drinks, stay as long as you want at Japanese Garden, and watch the sunset from the boat before heading back for dinner. It’s authentic, private, and surprisingly affordable if you split the cost.

Goodtime Adventures offers a more "active" snorkeling experience. They use speedboats or smaller vessels to get you to the spots faster, maximizing your time in the water. Their guides are often diving instructors, meaning they are incredibly knowledgeable about marine life. It’s perfect for solo travelers looking to make friends before the NYE countdown. They often combine snorkeling with cliff jumping or beach stops.

Sangthong is a classic Koh Tao institution. They run the famous "Round Island" trip on a larger, comfortable wooden boat. While it can be busier than the premium tours, it is very reliable and excellent value. They have a high success rate for finding turtles because their captains know the waters perfectly. The tour includes stops at all 5 major bays, including Shark Bay and a long stop at Koh Nang Yuan.

If you are traveling with a group of friends and want a fun, party vibe for NYE, Diamond Tour is a great pick. Their large boat features a water slide and a sundeck with bean bags. It’s less "serious" snorkeling and more "fun day out." They visit all the main spots (Shark Bay, Nang Yuan), and the atmosphere is lively with music and fresh fruit served all day. Great for saving money for the evening party!