Koh Samui's location in the Gulf of Thailand makes it a perfect base for exploring the surrounding islands and marine parks. Here are the best day trips you can take by boat.
Ang Thong National Marine Park
The crown jewel of Gulf island excursions. This archipelago of 42 islands features dramatic limestone cliffs, hidden lagoons, pristine beaches, and rich coral reefs. The famous Emerald Lake (Thale Nai) sits inside a collapsed cave on Mae Koh island — the views from the viewpoint are unforgettable. Full-day tours depart daily from Samui.
Koh Phangan
Best known for its Full Moon Party, but there's so much more to Phangan. Take the ferry across for a day of exploring Thong Nai Pan beaches, the beautiful Bottle Beach (accessible only by boat or a challenging hike), and the lush interior. The island has a wonderful bohemian vibe with excellent yoga retreats and organic cafes.
Koh Tao
The diving capital of Thailand. Even if you're not a diver, the snorkelling around Koh Tao is exceptional. Japanese Garden, Shark Bay, and Mango Bay offer encounters with sea turtles, reef sharks, and colourful tropical fish. The fast catamaran makes it a feasible day trip, though many people wish they'd stayed overnight.
Koh Madsum (Pig Island)
A charming little island just south of Samui, famous for its friendly resident pigs who roam the beach. It's a fun half-day trip, especially for families. The beach is beautiful and uncrowded, and several operators combine it with a snorkelling stop at nearby Koh Tan.
Five Islands (Koh Haa)
A group of small islands off Samui's north coast, perfect for a relaxed snorkelling trip. The coral here is healthy and colourful, and the waters are usually calm. Less touristy than Ang Thong, this is a good choice for those who prefer a quieter experience.
Tips for Boat Trips
- **Book through your accommodation** — we can recommend reliable operators for our tenants
- **Best season**: March to October for calm seas
- **Bring**: reef-safe sunscreen, snorkel gear (or rent on board), waterproof bag for valuables
- **Seasickness**: The Gulf is generally calmer than the Andaman side, but take precautions if you're prone