The first thing I noticed about Lazy Beach was the silence. No music, no bar, no longtail engines — just the sound of the Gulf of Thailand washing over white sand and the creak of a hammock somewhere in the trees. Koh Rong Sanloem is that kind of island. It’s only a short ferry ride from the chaos of Sihanoukville, but it feels genuinely remote in a way that most of Southeast Asia’s beaches stopped being a long time ago.
Koh Rong Sanloem (also spelled Koh Rong Samloem) is a small, forested island in Cambodia’s Sihanoukville province. Unlike its busier neighbour Koh Rong, most of Sanloem has no roads, no ATMs, and no all-night parties. What it does have is some of Cambodia’s best bioluminescent plankton, excellent snorkelling, and three distinct beaches that each attract a different kind of traveller.
Key takeaways
- Best time to visit: November to April (dry season, calm seas)
- Getting there: Ferry from Sihanoukville; journey ~45 minutes
- Main beaches: Saracen Bay, M’Pai Bay, Lazy Beach (4.6★ / 805 Google reviews)
- Top activities: Bioluminescent plankton, snorkelling, lighthouse hike, Clear Water Bay day trip
- ATM: None on the island — bring USD cash from Sihanoukville before you board
- Budget: Expect to spend $15–30/day on activities; most beaches and hikes are free
Top things to do on Koh Rong Sanloem
Explore Lazy Beach
Lazy Beach sits on the western side of the island, and with a 4.6-star rating from over 805 Google reviews it’s the highest-rated spot on Koh Rong Sanloem. Getting there is part of the appeal: you can take a short jungle trail from Saracen Bay (about 20 minutes on foot), or pay roughly $5 per person for a boat taxi. Either way, you arrive at a stretch of completely unspoiled sand with water that shifts from pale turquoise to deep blue in about ten paces.
There are a handful of bungalows and a small bar at the far end, but the beach itself is long enough that you can always find a quiet patch of your own. Bring plenty of water and a snorkel — the reef just offshore is accessible straight from the sand.
Hike to the old lighthouse
The lighthouse hike is one of the best things to do on Koh Rong Sanloem if you want a reason to leave the beach. The trail starts near Saracen Bay and cuts up through dense jungle before emerging at a concrete lookout tower with views across the island and out to the mainland. The path is unmarked in places and can be slippery after rain, so wear proper footwear and go in the morning before the heat builds.
The full return hike takes around two to three hours depending on your pace. Some guided day trips from Sihanoukville include the lighthouse as a stop alongside beaches and snorkelling. If you’d rather have someone else handle the logistics, the Full-Day Koh Rong Sanloem Beach Tour covers multiple highlights including the lighthouse in one trip.
Take a day trip to Clear Water Bay
Clear Water Bay is on the northern tip of the island, away from the main beach settlements, and the journey there is half the experience — a boat ride along the coastline with visibility down to the coral visible from the surface. The bay itself lives up to its name: the water is extraordinarily clear, with a reef that slopes gently from the beach into deeper water.
We spent an afternoon snorkelling over coral gardens and spotted reef fish, starfish, and the occasional sea cucumber. Day trips from Saracen Bay run most mornings; a shared boat for a group of four to six people typically costs $10–15 per person including the boat ride. Read our full guide to visiting Clear Water Bay for all the details.
Watch the bioluminescent plankton
Koh Rong Sanloem’s bioluminescent plankton is one of the most disorienting, genuinely magical things I’ve experienced anywhere. After dark, tiny phytoplankton in the shallow water emit a blue-green light when disturbed — swipe your hand through the water and it glows. Wade in up to your waist and every step leaves a trail of cold blue fire.
The effect is visible year-round but is strongest on moonless nights, which is the one piece of practical advice worth repeating: check the lunar calendar and don’t visit during a full moon, as the ambient light washes out the glow. Several operators in Saracen Bay and M’Pai Bay run evening plankton tours; the swimming with bioluminescent plankton tour from Sihanoukville is a popular option if you want a guide to take you to the best spot.
Go snorkelling
The waters around Koh Rong Sanloem are warm, clear, and reasonably well-preserved compared to much of coastal Cambodia. Snorkelling is possible from several beaches, but the best conditions are in the shallows off Lazy Beach and around the reef near Clear Water Bay. Visibility is typically best in the dry season (November to April), when the seas are calmer and there’s less sediment in the water.
If you don’t have your own gear, most guesthouses on Saracen Bay and M’Pai Bay rent masks and fins for $3–5 per day. For a more structured snorkel with an experienced guide who knows the best reef spots, the Koh Rong Samloem snorkelling adventure departs from Sihanoukville and covers the prime sites. For more on Cambodia’s underwater world, take a look at our guide to snorkelling in Cambodia.
Kayak or paddleboard at golden hour
The hour before sunset is the quietest on the island. Saracen Bay catches the last of the light on the water, and kayaking out into the bay during this window — with the jungle ridge reflected in glassy water — is one of those completely free, completely perfect travel experiences. Kayaks are available for rent at most guesthouses along Saracen Bay for around $5 per hour.
Stand-up paddleboarding (SUP) is available too — Pearl Beach Resort offers boards free to guests, which is worth factoring into your accommodation choice. Going slowly on a SUP at golden hour, with the jungle-covered ridge darkening above Saracen Bay and the water turning copper, is the kind of thing that makes you extend your stay by two nights. Paddling north along the coast also gives you views of the island from the water that you simply can’t get from the beach.
Join the beach cleanup
One of the things that stuck with me about Koh Rong Sanloem is that it still feels clean. Part of the reason for that is a voluntary beach cleanup scheme run by local businesses — join the cleanup in the morning and you get a free beer afterwards. It sounds like a gimmick, but in practice it’s a good way to meet other travellers, learn about the conservation challenges facing the island, and feel less like a passive visitor.
The cleanup runs most mornings and takes around an hour. Ask at any guesthouse in Saracen Bay about the current schedule. The organisation behind it — like most environmental work on the island — is volunteer-driven and genuinely local, which makes it worth supporting even if the free beer is the initial draw.
Try scuba diving in M’Pai Bay
Diving on Koh Rong Sanloem is centred around M’Pai Bay, the island’s small fishing village on the north-west coast. The sites here are undeveloped by the standards of Koh Tao or the Thai islands — you won’t find the infrastructure, but you will find uncrowded reef, reasonable visibility, and dive operators who actually know their sites well. Visibility is best between November and April.
PADI Open Water courses are available at a couple of operators in M’Pai Bay, and a two-dive fun dive typically runs $60–80 depending on the season and group size. Expect coral reef, small reef fish, and the occasional sea turtle; the sites lack the bio-diversity of the Thai dive hubs but compensate with near-complete absence of other boats. If you want to combine diving with a lighthouse hike and a beach day, M’Pai Bay is 20-30 minutes by boat taxi from Saracen Bay — most operators can arrange a full day if you ask the night before.
Hike or boat to Sunset Beach
Sunset Beach is on the south-west coast of Koh Rong Sanloem and is the least visited of the island’s main beaches. It’s accessible by jungle trek from Saracen Bay — the path takes about 45 minutes each way and is steep in places — or by a boat taxi from the main pier. TripAdvisor lists it among the top three sights on the island.
The beach faces west, which means the name is justified: on a clear evening the sun sets directly in front of you over open water. There’s almost nothing here in terms of facilities — no bar, no bungalows, just the beach — so bring water and go in the late afternoon if you want to catch the light at its best. The boat culture around Cambodia’s islands means chartering a private boat to get there and back is straightforward to arrange from Saracen Bay for around $10–15.
Which beach should you pick?
Most visitors end up choosing one base and staying there for their whole trip, so getting the choice right matters. Here’s a quick comparison:
| Beach | Vibe | Rating | Best for |
|---|---|---|---|
| Saracen Bay | Backpacker hub; most accommodation and restaurants | 4.0★ / 262 reviews (TripAdvisor) | First-timers, social travellers, day trip base |
| M’Pai Bay | Local fishing village; quieter; basic facilities | 4.5★ / 355 reviews | Divers, travellers wanting something authentic |
| Lazy Beach | Remote, mostly deserted; minimal development | 4.6★ / 805 reviews (Google) | Anyone wanting a day trip or overnight away from crowds |
Sunset Beach is a fourth option — smaller, west-facing, and completely undeveloped. No facilities, but a stunning view. Reach it by a 45-minute jungle hike or boat taxi from Saracen Bay. TripAdvisor ranks it among the top three sights on the island.
Koh Rong vs Koh Rong Sanloem: what’s the difference?
Koh Rong is the larger, more developed island — it has beach bars, ATMs (barely), a busier ferry service, and a party scene centred around Koh Tui Village. It’s popular and fun, but increasingly crowded in peak season.
Koh Rong Sanloem is smaller and much quieter. There’s no nightlife to speak of outside of a few guesthouses, no ATMs at all, and most of the island’s interior is accessible only on foot. If you’re choosing between them: Koh Rong for nightlife and convenience, Koh Rong Sanloem for nature and proper slow travel. Many visitors do both — ferries run between the two islands.
Practical tips
Best time to visit
November to April is the dry season and the best time to visit Koh Rong Sanloem. Seas are calm, the sky is reliably clear, and snorkelling and diving visibility is at its peak. December and January are the busiest months; if you visit in early November or late March you get good weather with significantly fewer fellow tourists.
May to October is the wet season — the island empties out, some guesthouses close, and the ferries can be cancelled in rough weather. That said, the bioluminescent plankton can be spectacular during these months, and accommodation prices drop considerably.
Activity costs
| Activity | Cost (approx.) |
|---|---|
| Snorkel gear rental (per day) | $3–5 |
| Kayak rental (per hour) | $5 |
| Boat taxi (one way, per person) | $5 |
| Clear Water Bay day trip | $10–15 |
| Bioluminescent plankton tour | $15–25 |
| Fun dive (2 dives) | $60–80 |
| Lighthouse hike | Free (self-guided) |
| Beach cleanup | Free + a beer |
Getting there and getting around
The ferry from Sihanoukville to Koh Rong Sanloem takes around 45 minutes. Two operators — GTVC and Speed Ferry Cambodia — run several crossings daily in peak season, with a reduced schedule in the wet months. Book early in December and January.
There are no roads between the main beaches, so getting around means boat taxis (~$5 per person between beaches) or jungle trails on foot. The walk from Saracen Bay to Lazy Beach takes around 20 minutes; the walk to M’Pai Bay is longer and more demanding.
Cash and ATMs
There are no ATMs on Koh Rong Sanloem. Most guesthouses and restaurants accept USD cash, and some accept card for larger payments, but don’t rely on it. Read our guide to getting cash near Koh Rong and withdraw before you board the ferry — $50–100 is a reasonable buffer for a three-night stay if you’re watching your budget. See our full cash guide for the best ATMs in Sihanoukville.
Frequently asked questions
What is the best beach on Koh Rong Sanloem?
Lazy Beach has the highest rating of any beach on the island — 4.6 stars from over 805 Google reviews — and the most pristine setting. For convenience and amenities, Saracen Bay is the most practical base. M’Pai Bay is the pick for anyone interested in diving or a more authentic local atmosphere.
What is the difference between Koh Rong and Koh Rong Sanloem?
Koh Rong is the larger, busier island with more bars, restaurants, and a party scene. Koh Rong Sanloem is smaller, quieter, and has almost no development outside of the beach settlements. They’re close enough that many visitors do both. Sanloem is the better choice if you’re looking for nature, hiking, and genuine peace and quiet.
When is the best time to visit Koh Rong Sanloem?
November to April. The dry season brings calm seas, clear skies, and the best visibility for snorkelling and diving. December is peak season; shoulder months like November and March offer nearly as good weather with fewer visitors.
How do you see bioluminescent plankton on Koh Rong Sanloem?
Walk into the sea on any dark night and swipe your hands through the water — the plankton will glow blue-green where it’s disturbed. The effect is strongest on moonless nights, so avoid travelling during a full moon. The best spots are in the shallows off Saracen Bay and the quieter beaches. Guided evening tours are available from operators in Saracen Bay and from Sihanoukville via a bioluminescent plankton swim tour.
Is Koh Rong Sanloem worth visiting?
Yes — if you want the kind of slow, unhurried beach experience that’s hard to find in Southeast Asia anymore. The bioluminescent plankton alone is worth the ferry ride. The lighthouse hike, Clear Water Bay, and Lazy Beach offer enough variety that a three to five day stay never feels repetitive. Just come prepared: bring cash, a snorkel, and a book.
Koh Rong Sanloem is best experienced slowly. The island rewards those who stay long enough to explore all four beaches, hike the lighthouse trail before breakfast, and spend an evening standing in glowing water with no idea where the sea ends and the sky begins. Pack your cash before you board — and read our guide to eating and sleeping on Koh Rong so you know exactly where to base yourself when you arrive.
