Koh Lanta 4 Islands Tour Review: Emerald Cave, Snorkelling & Prices
The Trang islands: a full day of caves, coral and white sand from Koh Lanta
The 4 Islands tour is the most popular day trip from Koh Lanta. In one day you swim through a pitch-black sea tunnel into a hidden lagoon, snorkel over coral and relax on white sand beaches in the Trang islands.
But is it worth it? This review covers what happens at each stop, exact prices from four sellers, longtail vs speedboat, the Emerald Cave tide trick and honest feedback from travellers.
The verdict
The 4 Islands tour is worth it for most visitors, especially first-timers and families with confident swimmers. The Emerald Cave swim is a real highlight. The beaches at Koh Kradan and Koh Ngai are beautiful too.
Book a longtail for the best value, or a speedboat if you want a shorter crossing. To avoid the worst crowds, ask your operator for the earliest or latest Emerald Cave slot.
What you'll see: the 4 stops
1. Emerald Cave (Koh Mook)
Emerald Cave, Koh Mook: life jackets on and follow the rope
Your boat stops at a low opening in the cliffs on Koh Mook's west side. Everyone puts on a life jacket and follows a rope through a tunnel about 80 metres long. The middle section is completely dark, so guides carry torches.
Emerald Cave, Koh Mook: a hidden beach ringed by limestone walls
You come out on a small hidden beach surrounded by tall limestone walls. One Tripadvisor reviewer said "the Emerald cave was the highlight" and the swim was "fairly easy."
2. Koh Chueak
Koh Chueak: a snorkelling stop with soft corals
Koh Chueak is a small limestone rock with no beach, used only for snorkelling. Expect soft corals, parrotfish and sergeant majors. It's usually quieter than the other stops, but currents can be strong. One traveller found fish here but not many species.
3. Koh Ngai
Koh Ngai: lunch and a swim on a long white beach
Koh Ngai has a long white beach on its east coast, with shallow coral just offshore. Most longtail tours stop here for a Thai picnic lunch and a swim. Some tours add nearby Koh Maa for extra snorkelling.
4. Koh Kradan
Koh Kradan: clear shallow water and a reef on the east side
Koh Kradan is usually the final stop. It has a long white beach, clear shallow water and a reef on the east side. Plan for 60 to 90 minutes here. Speedboat tours often have lunch on this beach.
Typical day timeline (longtail)
| Time | What happens |
|---|---|
| 8:00am to 8:30am | Hotel pickup |
| 9:00am | Depart Koh Lanta |
| 10:00am | Swim through the Emerald Cave |
| 11:30am | Snorkel at Koh Chueak |
| 12:30pm | Lunch and swim on Koh Ngai |
| 2:00pm | Beach and snorkelling on Koh Kradan |
| 3:30pm | Head back to Koh Lanta |
| 4:30pm to 5:30pm | Hotel drop-off |
The order changes with the tide, since the Emerald Cave can only be entered at low to mid tide.
Exact prices from 4 sellers (October 2026)
| Seller | Boat | Adult | Child | Park fee included? | Link |
|---|---|---|---|---|---|
| Koh Lanta Tours | Longtail | ฿995 | ฿895 (ages 4 to 11) | No | View tour |
| Monkey Tours Lanta | Longtail | ฿1,000 | Not listed | No | View tour |
| Big Tour Krabi | Speedboat | ฿1,349 (was ฿1,600) | ฿699 (was ฿800) | No | View tour |
| Koh Lanta Tours | Speedboat | ฿1,550 | ฿1,350 (ages 4 to 11) | No | View tour |
| Monkey Tours Lanta | Speedboat | ฿1,800 | Not listed | No | View tour |
National park fee (all tours): ฿200 per adult and ฿100 per child, paid in cash on the day.
- Big Tour Krabi adds a 4% processing fee for online payment.
- Koh Lanta Tours says its speedboat lunch has halal and vegetarian options. Ask your operator if you need halal food.
- Infants aged 1 to 3 go free with Koh Lanta Tours.
Private boats: a private longtail for up to about 8 people costs ฿5,000 to ฿8,000 per boat. A private speedboat costs ฿12,000 to ฿25,000 per boat, according to one 2026 guide.
Longtail vs speedboat
Koh Lanta pier: longtail for value, speedboat for speed
| Longtail | Speedboat | |
|---|---|---|
| Price | From ฿995 | From ฿1,349 |
| Crossing time | About 1 to 1.5 hours | About 30 to 45 minutes |
| Total day | 7 to 8 hours | 6 to 7 hours |
| Comfort | Louder and wetter in choppy seas | Faster, but bumpier at the front |
| Group size | Usually smaller | Usually larger |
| Best for | Budget travellers and slow days | Families and those prone to seasickness |
Emerald Cave tips
- Mind the tide. The cave entrance is only passable at low to mid tide.
- Avoid the rush. Many boats arrive between about 10am and 2pm. Queues can form in the water.
- Ask for the first or last slot of the day for fewer boats.
- Non-swimmers can still go. Life jackets are worn and a rope guides the way. Tell your guide if you're nervous.
- Young kids may find it scary. The tunnel is pitch black. An adult may need to stay on the boat with them.
Is it good for kids?
Koh Kradan: shallow water that kids love
It suits children who are comfortable in the water. Koh Ngai and Koh Kradan have shallow beaches that are great for paddling. A speedboat shortens the crossing for younger kids. It's a long day, so pack snacks and plan a quiet evening.
What to bring
- Cash in small notes for the park fee, drinks and coconuts.
- Reef-safe sunscreen. Some chemicals are banned in Thai marine national parks.
- A dry bag for your phone and valuables.
- Swimwear under your clothes, since boats have no changing rooms.
- Seasickness tablets taken 30 to 60 minutes before departure.
- A waterproof phone case for photos in the lagoon.
Best time to go
Go between November and April for the calmest seas and clearest water. December to February is the busiest time, so book 1 to 2 days ahead. May and October are shoulder months with possible cancellations. June to September brings rough seas and park closures.
Pros and cons
Pros
- The Emerald Cave swim is unique and memorable.
- Beautiful white sand beaches at Koh Kradan and Koh Ngai.
- Good value, with longtail tours from under ฿1,000.
- Lunch, snorkel gear and hotel transfers are usually included.
Cons
- The Emerald Cave can be very crowded.
- Group sizes can be larger than advertised.
- Snorkelling at Koh Chueak can be average.
- The boat ride back can be rough.
Common mistakes to avoid
- Forgetting cash for the ฿200 park fee.
- Booking in June to September, when the islands may be closed.
- Sitting at the front of a speedboat if you get seasick.
- Using regular sunscreen in the marine park.
- Expecting the Emerald Cave to be empty at midday.
Sourced from KOHME 4 Islands Tour Koh Lanta 2026, Koh Lanta Tours' longtail and speedboat tour pages, Big Tour Krabi, Monkey Tours Lanta, Tripadvisor reviews and a Vakantio travel blog. Prices checked in October 2026.