You can take plenty of adventures that are only i short boat ride away from Koh Samui. From secluded islands to bustling marine parks, the waters surrounding Koh Samui offer day trips that bring the best of Thailand’s natural beauty right to your doorstep. Whether you’re searching for underwater marvels, hidden lagoons, or scenic beach escapes, here’s a guide to the must-do boat trips that will take your Koh Samui experience to the next level.

1. Ang Thong National Marine Park: A Nature Lover’s Paradise

Ang Thong National Marine Park Long term rental Samui

A short boat ride from Koh Samui, Ang Thong National Marine Park boasts 42 emerald islands dotting the Gulf of Thailand. This marine park is a smorgasbord of breathtaking views, secret lagoons, and coral gardens teeming with colourful marine life. For day-trippers, this is a chance to step into a natural wonderland.

Begin with a stop at Koh Mae Ko, known for its inland Emerald Lake, a turquoise gem tucked away amidst towering limestone cliffs. Climb up the steep staircase to the viewpoint for a bird’s-eye view of the lake—it’s worth every drop of sweat.

Then, kayak around the islands or snorkel to glimpse coral reefs and schools of tropical fish. Ang Thong offers a taste of paradise that’s as close as it gets to untouched beauty.

2. Koh Phangan: Beyond the Full Moon Party

Koh Phangan Long term rental Samui

Koh Phangan is world-famous for its monthly Full Moon Party, but there’s so much more to this island than beach revelry. Just a short boat ride away from Koh Samui, Koh Phangan offers pristine beaches, dense jungle, and cascading waterfalls waiting to be explored.

Hop on a boat early in the morning to arrive as the island stirs awake, then head to Bottle Beach, one of Koh Phangan’s best-kept secrets. Accessible mainly by boat, this secluded stretch of sand offers turquoise waters perfect for swimming and snorkelling, and a serene escape from the bustling beaches of Samui.

If you’re feeling adventurous, trek up to the Bottle Beach viewpoint and soak in the panoramic views of the coast.

3. Koh Tao: The Diver’s Dream

For those who dream of plunging into crystalline waters to explore vibrant coral reefs, Koh Tao is the ultimate day trip. Known as a diver’s paradise, this island draws enthusiasts from all over the world with its rich underwater ecosystem.

Board an early ferry or speedboat, and you’ll arrive just in time for a morning dive session. Here, you’ll find dive sites like Shark Bay, where (harmless) blacktip reef sharks often make an appearance, or Chumphon Pinnacle, renowned for its schools of barracudas and colourful corals.

For non-divers, Koh Tao offers some incredible snorkelling spots where you can still enjoy the underwater spectacle without the tanks. Afterwards, relax on Sairee Beach, the island’s longest stretch of sand, and savor a beachfront lunch before heading back.

4. Koh Madsum (Pig Island): A Quirky Beach Adventure

Koh Madsum Long term rental Samui

A trip to Koh Madsum, also known as Pig Island, offers visitors a day of laughs and sandy relaxation. A short boat ride from Koh Samui, Koh Madsum is famous for its unusual residents—friendly pigs that wander the beaches and welcome visitors.

Arrive ready to interact with these quirky beach companions, and bring your camera because the sight of pigs paddling in the shallow waves is a photo opportunity you won’t find every day.

After bonding with your new porcine pals, relax on the beach, swim in the clear waters, or enjoy a traditional Thai lunch at a nearby restaurant. It’s an experience that mixes the beautiful with the bizarre, a perfect blend for a memorable day out.

5. Koh Tan: The Snorkeler’s Secret

Koh Tan Long term rental Samui

While Koh Tao often steals the limelight for snorkelling, Koh Tan, just off the southern coast of Koh Samui, holds its own as a stunning destination for marine adventures. Known locally as “Coral Island,” Koh Tan offers coral reefs bursting with marine life, from clownfish to sea anemones.

Many boat tours include snorkelling stops around Koh Tan, where you can dive into warm waters and swim alongside a vibrant underwater world.

The island itself has no cars or paved roads, offering an escape from the modern world and letting you bask in the beauty of untouched nature. After snorkelling, you can explore the rustic island trails or simply unwind on the quiet beaches, where you’ll often have the sand to yourself.

6. Koh Nang Yuan: A Photographer’s Dream

Koh Nang Yuan Long term rental Samui

Just a hop, skip, and a jump away from Koh Tao lies Koh Nang Yuan, a trio of islands connected by sandy causeways, forming one of Thailand’s most iconic beach landscapes. A boat ride to this postcard-perfect destination brings you to powdery sands flanked by turquoise waters on either side—a scene straight out of a dream.

Take a hike up to the island’s viewpoint, where a panoramic view of the sandbars awaits. It’s the kind of view that will make your friends back home green with envy.

For snorkelers and divers, the waters around Koh Nang Yuan teem with marine life, so be sure to pack your gear. Just remember, the island operates with a “no plastic” policy, so come prepared to carry out anything you bring in.

7. Sail Rock: An Offshore Adventure for Experienced Divers

For seasoned divers, a trip to Sail Rock is a bucket-list experience. This underwater rock formation, about halfway between Koh Samui and Koh Tao, is famous for its stunning vertical wall dive, where you’ll encounter everything from giant barracuda to the occasional whale shark.

While this trip requires some diving experience, it’s an adventure unlike any other, as you’ll dive down the “chimney”—a unique swim-through rock formation that takes divers from a depth of 5 meters to 18 meters.

It’s a surreal, almost otherworldly experience that makes the journey to Sail Rock unforgettable. For non-divers, some boat operators offer snorkelling trips here, giving everyone a chance to enjoy the splendour of Sail Rock.

Choosing Your Perfect Day Trip

Each of these boat trips offers a unique glimpse into Thailand’s marine splendour, so the choice depends on your interests. For nature lovers and kayakers, Ang Thong National Marine Park is a must.

Divers should look no further than Koh Tao or Sail Rock, while those seeking quirky adventures should set sail for Koh Madsum. And for the intrepid traveller with a camera in hand, Koh Nang Yuan is simply unmissable.