An Thoi Islands Snorkeling: Ride South and Dive In
By Alex Nguyen · Updated July 2026 · 6 min read
The clearest coral reefs on Phu Quoc hide beneath the waters off the An Thoi archipelago, a cluster of 18 islands at the island's southern tip. Snorkel or free-dive above gardens of hard and soft coral teeming with parrotfish, angelfish and sea turtles — all reachable by a scenic motorbike ride south to An Thoi harbour where wooden day-boats depart on most mornings — confirm schedules with operators locally.
Why Snorkel at An Thoi — Phu Quoc's Best Coral
The An Thoi islands sit in the Gulf of Thailand roughly 3–5 km off Phu Quoc's southern coast, protected from the open South China Sea. That sheltered position keeps the water calmer and clearer than reef sites closer to Duong Dong. Local dive operators consistently rate the waters around Hon Thom (Pineapple Island), Hon Mong Tay and Hon Roi among the best snorkeling spots in southern Vietnam, with visibility sometimes reaching 15 metres during the dry season.
Hard coral coverage at Hon Thom's northern shallows starts at just 1–2 metres, making it ideal for snorkelers who prefer not to dive deep. You will often share the water with schools of blue-striped snapper, lionfish hovering near coral heads, and the occasional reef shark patrolling further out — all signs of a healthy marine ecosystem.
The Ride: Motorbike Route to An Thoi Harbour
An Thoi town is about 27 km south of Duong Dong along the main coastal road (QL47D). The ride takes roughly 35–45 minutes on a scooter and passes through Duong To village, the pearl-farm coast, and the salt flats near Ba Keo beach — a scenic journey worth taking slowly. Automatic scooters like the Honda Vision or Airblade handle the route effortlessly; the road is well-surfaced all the way to the harbour.
Park near the An Thoi ferry terminal or along the waterfront. GoBike delivers bikes free, 24/7, directly to your hotel, so you can leave first thing in the morning and arrive at the dock before most tour boats depart. Boat operators usually gather customers at the pier — check current departure times and prices with them on the day, as schedules vary by season and group size.
- Distance: — ~27 km from Duong Dong town centre to An Thoi pier.
- Ride time: — 35–45 minutes at a relaxed pace.
- Road condition: — Paved and well-maintained for the full route.
- Parking: — Roadside parking is usually available near the harbour; check locally as conditions vary.
Islands and Reefs You Can Snorkel
Hon Thom (Pineapple Island) is the largest island in the An Thoi group and the most visited snorkeling stop. Its northern reef flat hosts staghorn and brain corals, moray eels and clownfish in anemones. Water time at each stop is operator-dependent — check the schedule with your boat before boarding.
Hon Mong Tay (Cannon Island) offers a shallower reef suitable for beginners and children. The calm bay on the western side has sandy patches between coral bommies, making it easy to rest and re-enter the water. Hon Dam and Hon Roi (Lantern Island) are further stops on some extended tours, with fewer visitors and more intact coral walls.
Island-hopping routes vary — some boats visit 3 stops, others 4–5. Discuss the itinerary with your boat captain before boarding. Always ask which islands are included rather than assuming; prices and routes are not standardised across operators.
What to Bring for a Snorkeling Day Trip
Most An Thoi day-boat operators provide basic snorkeling masks and fins included in the tour price, but quality varies. Bringing your own mask guarantees a proper fit and a fog-free experience. A rash guard or thin wetsuit protects against jellyfish and sunburn — surface temperatures in the dry season stay around 28–30 °C, comfortable for hours of swimming.
Pack reef-safe sunscreen (many operators now ban oxybenzone-based creams to protect coral), a towel, waterproof bag for your phone, plenty of water and snacks. Boats usually sell drinks on board but at tourist prices. Leave valuables in your guesthouse safe rather than in your motorbike's underseat storage.
- Essentials: — Mask & fins (own preferred), rash guard, reef-safe sunscreen.
- Documents: — Keep your passport or ID at the guesthouse; take a photo copy.
- Cash: — Bring Vietnamese Dong for boat fees, drinks and shore snacks — card machines are rare at the pier.
- Seasickness: — If you are prone, take medication before boarding; the open channel to Hon Thom can be choppy outside peak dry season.
Best Season for Clear Water and Calm Seas
The dry season from November to April delivers the finest snorkeling conditions around An Thoi. Northeast winds are light, wave heights stay low, and water clarity peaks — visibility of 10–15 metres is common at Hon Thom in January and February. Sea temperatures hover around 27–29 °C, making extended snorkeling comfortable without a wetsuit.
The rainy season (May–October) brings stronger southwest monsoon winds that reduce visibility and increase wave heights, particularly in July and August when some boat tours are suspended on rough days. Late October and early November can still be excellent as winds shift; check conditions locally before booking. Even in shoulder months, calm mornings often allow safe snorkeling — ask the boat captain the evening before about the next day's forecast.
Combining Snorkeling with a Full Southern Phu Quoc Day
An Thoi is more than a boat terminal. The town itself has a lively morning fish market on the waterfront and a handful of seafood restaurants serving the catch of the day. After a morning snorkel tour, explore the southern coast road back towards Duong Dong, passing scenic viewpoints above the pearl farms and the mangrove inlet near Ham Ninh fishing village.
Ham Ninh is a worthwhile 10-minute detour off the main road — a stilted fishing village with crab and squid grilled on the pier. Continuing north, stop at Sao Beach (Bai Sao) for a late afternoon swim in the famous white sand bay before riding back to your hotel. Free 24/7 bike delivery means you can time your return without rushing, and booking online takes just a minute — leaving the whole day free for water and islands.
Frequently asked questions
Do I need to book an An Thoi snorkeling boat tour in advance?
Walk-up bookings are often possible at the pier, especially in low season, but pre-booking through your guesthouse or a local operator is safer during the November–April peak. Check current availability and prices locally, as they are not standardised.
Can a beginner snorkel at An Thoi islands?
Yes — Hon Mong Tay and parts of Hon Thom have shallow, calm reef flats suitable for absolute beginners. Life vests are available on all boats, and guides are present. No prior swimming certification is needed.
How long is the motorbike ride from Duong Dong to An Thoi harbour?
The ride is approximately 27 km and takes 35–45 minutes at a relaxed pace on a well-paved coastal road. An automatic scooter handles the full route easily.
Is snorkeling at An Thoi possible during the rainy season?
It can be, but conditions are unpredictable. Southwest monsoon winds from May to October reduce visibility and increase wave heights. Calm mornings sometimes allow trips — always confirm with your boat operator the day before.
What marine life can I see snorkeling around An Thoi?
Expect hard and soft corals, parrotfish, angelfish, blue-striped snapper, moray eels, clownfish in anemones, lionfish and, on lucky dives, sea turtles and small reef sharks at Hon Thom and Hon Roi.