An Thới Islands Snorkeling: Phú Quốc's clearest water

You can see the An Thới islands from the south tip of Phú Quốc — a low chain of green humps scattered across pale-blue water. Closer up, the water turns the colour of swimming-pool glass and the reefs come into focus. An Thới islands snorkeling is one of the few things on this island we’d push every guest to do at least once.

It’s not a long day. The boat leaves around nine, you’re back at Luna by four with sun on your shoulders and salt in your hair. Three stops, a lazy lunch, no rush.

Why An Thới — and not somewhere else

Phú Quốc has snorkeling on most of its coasts, but the An Thới archipelago in the south has the clearest water and the healthiest reef. Fifteen small islands, mostly uninhabited, with sheltered bays that stay calm even when the open sea is choppy. The coral here is softer and more colourful than the coast — fans, brain coral, the occasional purple anemone — and the fish are small but plentiful.

From Luna it’s a 45-minute drive south to An Thới harbour. We arrange a car the night before so you don’t waste the morning negotiating with a taxi. The boat captains we work with run wooden vessels with shade, life jackets in the right sizes, and a captain who won’t push you to buy anything on board.

The three islands you’ll see

A standard An Thới snorkeling tour visits three of the bigger islands in the archipelago. Captains vary the route based on wind and where the cruise crowds aren’t.

Hòn Móng Tay

A long sandbar with shallow water on the east side. The reef sits about a hundred metres off the beach — you can swim out or take the dinghy. We usually stop here first because the water is calmest in the morning and the visibility is at its best.

Hòn Gầm Ghì

The smallest of the three, but our favourite. There’s a fringing reef on the west side where parrotfish come up to feed. The coral is more colourful here than anywhere else in the trip.

Hòn May Rút

The lunch stop. White sand, palm trees, a few simple thatched huts where the boat ties up. Lunch is grilled fish, rice, vegetables and fruit — laid out on the deck or a beach table depending on the boat. After eating, most guests just float for an hour before the last snorkel.

A wooden boat moored at one of the An Thới islands — what most of the day looks like.

When to go (and when to skip)

The dry season — November to May — is when An Thới snorkeling is at its best. The sea is calm all day, the water is clear, and the morning sun lights up the reef. Pick a morning trip if you can; afternoon wind tends to pick up and stir the surface.

From June through October the water is still warm and pleasant, but afternoon storms are common and visibility drops after rain. We still send guests out on clear mornings in the green season — you just need to be flexible and watch the weather the night before. If a day looks bad, we’ll move you to the next clear one.

The full moon and new moon weeks bring stronger currents. The boats know which spots to avoid, but visibility is sometimes a bit lower then.

What to bring (and what we pack for you)

Bring as little as possible — the boat is small and you’ll be wet most of the day.

• Reef-safe sunscreen. The sun is brutal on the water. We keep a bottle at reception if you forgot.
• A hat and a long-sleeve rashguard. Better than re-applying sunscreen all day.
• A dry bag for your phone and a small towel. Most boats provide towels but bring your own to be sure.
• Cash for tips and any extras at the lunch island.

What’s already on the boat: snorkel mask, fins, life jacket, drinking water, lunch, and a basic first-aid kit. If you wear glasses, ask Luna the day before — some captains have prescription masks in common strengths.

How we book it from Luna

We don’t run the boat ourselves — we work with two captains we trust, both based at An Thới harbour. The price from Luna is 850,000 ₫ per person for a full-day shared boat (kids under 10 are 500,000 ₫). That includes the car from SS27 Sonasea, the boat, all gear, lunch and an English-speaking guide.

If your group is four or more we can arrange a private boat so you set the pace and skip the bigger islands when they’re crowded. Tell us at check-in — we’ll confirm by the next morning.

Luna is on Bãi Trường, which is the closest stretch of coast to An Thới harbour, so the morning drive is short — you’ll be on the boat before the cruise-day crowds arrive. Have a look at the rooms if you’re still planning the trip, or send us a note via contact and we’ll hold a date.

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Photos: hero — Bernd Dittrich on Unsplash; in-body — Vivu Vietnam on Unsplash.