4 Islands & Emerald Cave
The classic Lanta day out, on a traditional longtail
Koh Ngai, Koh Maa, Koh Kradan and the swim-in Emerald Cave at Koh Mook — a full day at an unhurried longtail pace, and the cheapest island day we run.
This is the trip most people picture when they think of Koh Lanta, and on a longtail it is also the best value. A traditional wooden boat leaves from Lanta Old Town and works its way south-east across calm morning water to a string of small islands, each one a different kind of snorkeling.
The centrepiece is Tham Morakot — the Emerald Cave — on Koh Mook. You swim about eighty metres through a dark limestone tunnel, holding a float line, and come out on a hidden beach ringed by cliffs with a circle of open sky above it. There is no other way in.
The longtail is slower than a speedboat and that is the point: more time in the water, fewer people at each stop, and an engine you can talk over. Lunch is a buffet on the beach at Koh Kradan.
Highlights
- Swim the 80m tunnel into the Emerald Cave
- Shallow, calm coral gardens at Koh Maa
- Buffet lunch and beach time on Koh Kradan
- Soft coral and tropical fish at Koh Chueak
- Slow pace — real time in the water at every stop
How the day runs
- 07:30–08:00
Hotel pickup
We collect you from your resort anywhere on Koh Lanta Yai.
- 08:30
Sail for Koh Ngai
Depart Lanta Old Town. Safety briefing and gear fitting on the way out, then sightseeing around Koh Ngai.
- 10:40
Koh Maa, then lunch on Koh Kradan
Snorkeling at Koh Maa, then buffet lunch and time on the beach at Koh Kradan — some of the whitest sand in Thailand.
- 13:30
Emerald Cave, Koh Mook
Swim the tunnel in a small group with your guide and a float line, out to the hidden beach inside.
- 14:30
Koh Maa or Koh Chueak
A last snorkel, wherever the water is clearest that afternoon.
- 15:00
Sail home
Back to Koh Lanta and a transfer to your resort.
Times are indicative. Sea state, tide and the national park can all shift the running order — your guide will tell you on the morning if anything changes.
What's included
- Hotel pickup and drop-off on Koh Lanta Yai
- Mask, snorkel and fins
- Life jacket and float ring
- Buffet lunch, fresh fruit, soft drinks and drinking water
- Experienced local guide in the water with you
- Insurance
Not included
- National park fee — THB 200 adult / THB 100 child, paid on the day
- Towels
- Alcoholic drinks
Where this trip goes
Before you book
- Fitness: Easy–Moderate. Life jackets and float rings are on board and a guide stays with anyone who is not a confident swimmer.
- Bring: a towel, a rash vest, reef-safe mineral sunscreen, a dry bag, and cash in baht for any national park fee.
- Weather: if we cancel for sea conditions you get a full refund or a free move to another day.
- Reef rules: no standing on coral, no touching wildlife, no feeding monkeys, and no sunscreen containing filters banned in Thai marine parks.
Other trips you might prefer
Half a day, your own boat, one very good reef
Stops Koh Mah
Best for familiesThe clearest water in reach of Lanta, and the whole boat is yours
Stops Koh Haa
Best snorkelling
The trip we are named for
Stops Lanta east coast mangroves · Monkey Point · Talabeng sea caves
Best for families