- The Tup Island sandbar, called Talay Waek ("separated sea"), rises between Koh Tup, Koh Kai (Chicken Island) and Koh Mor only around low tide.
- Low tide moves later by roughly three quarters of an hour each day, so the best slot for the sandbar changes through the week.
- A private boat can choose the order of the 4 Islands stops, which is the easiest way to reach the sandbar near low water.
- The Power Catamaran 40ft runs the 4 Islands as a half day for ฿22,000 or a full day for ฿29,000, for 1-10 guests.
- The Long-tail Boat costs ฿8,900 for a half day and ฿15,000 for a full day, and the Luxury Long-tail ฿6,900 for 4 hours for 2 guests.
The boat slows down, the water under the hull turns from blue to pale green, and suddenly people are standing in the middle of the sea up to their ankles. That is the Tup Island sandbar at the right moment. Arrive two hours later and the same spot is a swim between two islands, pretty, but not the walk you came for.
This is a guide to getting that timing right: what the sandbar is, when it shows, what Chicken Island offers next to it, and how a private boat from Ao Nang or Railay plans the day around the tide instead of around a fixed schedule.
Where is the Tup Island sandbar, and what is Talay Waek?
The Tup Island sandbar is a strip of white sand that connects Koh Tup, Koh Kai (Chicken Island) and the tiny Koh Mor at low tide. Locals call the spot Talay Waek, which means "separated sea", because the sand seems to split the water in two.
The three islands sit a short ride off the coast of Ao Nang, inside the Hat Noppharat Thara - Mu Ko Phi Phi National Park. They are part of the classic 4 Islands trip by private boat, together with Koh Poda and Railay. Because the park covers the area, a park fee may be collected on the day, and it is not part of the boat price.
Koh Tup is the small, flat-topped rock with a sliver of beach. Chicken Island is the taller one with the famous rock "head" at its tip. Between them, at low water, the sand rises and you can walk from one island to the other. At high water, there is still a beautiful shallow stretch, but the walk becomes a wade or a swim.
It is worth saying clearly: the sandbar is not a huge beach. It is a narrow ribbon, sometimes only a few metres wide, and it looks best from the boat or from a drone. Standing on it is the fun part, not lying on it all afternoon.
When does the Tup Island sandbar appear?
The sandbar appears around low tide and starts to disappear as the water comes back in. As a rough guide, the best window is about an hour or two either side of low water, but the exact shape changes with the day.
The Andaman Sea here has two high tides and two low tides on most days. Low tide moves later by roughly 45 to 50 minutes each day, so if the sandbar is perfect at 10:00 on Monday, it will be closer to lunchtime by Wednesday. This is the single fact that decides your plan.
Not all low tides are equal either. Around the full moon and the new moon the tides are stronger, and the low water drops further, so the sandbar is wider and stays dry for longer. In between, during the weaker neap tides, the bar may only just break the surface, and some days it barely shows at all.
How do you check? Tide tables for Krabi are easy to find in tide apps, and the boat captains read them every day. Do not rely on a screenshot from someone else's trip. Look at the date you are actually going and note the time of the lowest water during daylight hours.
- Best case: a strong low tide during daylight, in the morning or mid-afternoon.
- Workable: a moderate low tide, where the bar shows as a shallow ridge you can wade along.
- Disappointing: a weak low tide very early or after dark, when you will see water, not sand.
If the sandbar is the main reason for your trip, choose the date first and the boat second. A flexible group that can move the trip by a day or two often gets a much better sandbar than a group that books a random date.
What is Chicken Island like for snorkelling?
Chicken Island is the best snorkelling of the four stops, mostly along the rocky side near its "chicken head" tip. The reef there is close to the surface, so you see a lot even without diving down.
Expect small reef fish in good numbers, and on a calm day clear enough water to watch them from the boat. Visibility is not Similan-level: after rain or with a swell from the south-west it gets cloudy. On a good dry-season morning, though, it is a pleasant, easy snorkel that suits beginners.
A few honest notes. The reef is shallow, so at low tide some of the coral is very close to your knees. Never stand on coral, wear a vest if you are not a strong swimmer, and keep away from the long-tails that come and go. The rocky side can have a current near the tip, so stay with your group and listen to the crew.
Also, the low tide that makes the sandbar perfect makes snorkelling a bit trickier over the shallowest reef. Many captains solve this by snorkelling on the deeper side of Chicken Island first or last, and walking the sandbar in the middle of the low-water window. It is one of the small things a private boat can do and a shared tour usually cannot.
The snorkelling masks are included on the Luxury Long-tail and the Power Catamaran 40ft. On the Long-tail Boat the inclusions list life vests, towels and drinks, so if you want a mask, ask when you book or bring your own. A mask that fits your face is worth packing anyway.
How does a private boat time the sandbar stop?
A private boat times the stop by changing the order of the islands. The crew checks the tide for your date and puts Talay Waek where the low water falls, then fits Koh Poda, Chicken Island snorkelling and Railay around it.
Shared tours run one fixed route for everyone, so the sandbar is wherever it lands on the clock. On a private charter, the whole boat is for your group, so you can ask to go to the sandbar first, last or in the middle. Ask for this when you send the request, not on the morning of the trip.
Here is how the time slots of the three boats on this topic look, with the prices for the whole boat from each boat page:
| Boat | Trip | Time | Price per boat |
|---|---|---|---|
| Long-tail Boat (up to 8) | Half day morning | 09:00-13:00 | ฿8,900 |
| Long-tail Boat (up to 8) | Half day afternoon | 14:30-18:30 | ฿8,900 |
| Long-tail Boat (up to 8) | Full day | 09:00-17:00 | ฿15,000 |
| Luxury Long-tail (up to 6) | Half day trip | 4 hours | ฿6,900 for 2 guests |
| Power Catamaran 40ft (up to 25) | 4 Islands half day | 08:00-13:00 or 14:00-19:00 | ฿22,000 for 1-10 guests |
| Power Catamaran 40ft (up to 25) | 4 Islands full day | 10:30-19:30 | ฿29,000 for 1-10 guests |
The logic is simple. If low tide is in the morning, take a morning half day and go to the sandbar early. If low tide is mid-afternoon, the afternoon slot is better, and you also get the softer light on the limestone. If the tide is awkward, around midday for example, a full day gives the crew enough room to wait for it.
Two sample plans from experience:
- Low tide around 10:00. Morning half day: straight to Talay Waek, walk the sand, then snorkel the deeper side of Chicken Island, then a swim at Koh Poda before the beach gets busy.
- Low tide around 16:00. Afternoon half day: Poda or Railay first while the water is still high, then Chicken Island snorkelling, and the sandbar as the last stop when the sand is widest.
One more tip: the sandbar gets busy right at the moment it looks best, because every boat out there reads the same tide table. On a private boat you can arrive a little before the peak, when the sand is just showing, and enjoy the place before the crowd lands.
Which boat is best for Chicken Island and the sandbar?
For couples and small groups, a long-tail is the most natural boat for the sandbar. For families and bigger groups who want shade, space and a toilet that is not a squeeze, the Power Catamaran 40ft is the comfortable choice.
The Long-tail Boat is a teak boat for up to 8 guests, with a sun deck, a JBL speaker, an outdoor shower and a toilet on board. A captain and a butler look after you, and soft drinks, infused water, local snacks and a beach picnic are included. It has a shallow draft, so it can anchor close to the sand, and it is the only one of the three with a full day option at a long-tail price.
The Luxury Long-tail Boat is the slow, beautiful option: hand-made, modelled on the Thai boats of the 19th century, for up to 6 guests. The 4-hour trip is ฿6,900 for 2 guests, and each extra guest from 3 to 6 adds ฿1,000. Four hours is enough for Chicken Island and the sandbar if the tide is on your side, but it is not a day for all four islands at a relaxed pace. Ask the team which stops fit into that time on your date.
The Power Catamaran 40ft runs the actual 4 Islands route: Poda, Chicken Island, Talay Waek and Railay. The half day is ฿22,000 and the full day ฿29,000 for 1-10 guests, with each extra adult at ฿600 and each child aged 3-12 at ฿300, up to 25 guests. Snorkelling gear, a paddle board, a kayak, fruit and drinks are on board, and the bow net is a lovely place to watch the shallows. It anchors further out than a long-tail, so the crew uses the dinghy or you swim in.
My honest pick: a couple who mainly wants the sandbar and a snorkel should book a long-tail on the right tide. A family with grandparents or small kids, or anyone who gets seasick easily, should take the catamaran: two hulls roll less, and there is real shade.
Here are the three boats side by side, so you can open each page and compare what is included:
If your group is larger than 25, the Power Catamaran 72ft also runs a 4 Islands cruise, but that is a different kind of day and worth its own planning.
What can go wrong at the sandbar?
The main risks are the wrong tide, the crowds and the weather. None of them ruin the trip, but each can change it.
The wrong tide is the most common disappointment, and it is avoidable: check the date and say clearly in your request that the sandbar matters to you. Crowds are harder. The 4 Islands is the most popular day trip from Ao Nang, and in high season the sandbar and the beach on Koh Tup fill with shared-tour boats around late morning. Going early or late is the cure.
Weather is the third factor. From about May to October the south-west monsoon brings swell onto the Andaman Sea, and routes can change or be cancelled on rough days. The islands are close to the coast, so the 4 Islands still runs on many monsoon days, but the water is less clear and the long-tail ride gets bumpy. The month by month sea guide for Krabi covers this in more detail.
Smaller things: the sun on white sand is fierce, and there is no shade on the bar itself. Sharp shells and bits of coral hide in the sand, so reef shoes or old sandals help. And when the tide turns, it turns steadily: do not wander off to the far end of the bar as the water rises.
Is the Tup Island sandbar worth it, and who should skip it?
Yes, if you hit a good low tide in good light. Walking across the sea between two limestone islands is one of those simple moments people remember, and Chicken Island next door gives you the best snorkel of the day.
It is less worth it if your only possible date has a weak low tide after dark, or if you expect a long, quiet beach. In that case, put the time into a longer swim at Koh Poda or a stop at Railay, and treat Talay Waek as a short look from the boat.
Who should choose something else? Divers and keen snorkellers who want big reefs will find Chicken Island pleasant but limited. Groups who want dramatic scenery more than beaches often enjoy Hong Island and its lagoon more. And if you love the idea of the beach at Railay most, read the Railay Beach boat guide before you choose the route.
Before you book: a short practical checklist
Send the request with the details that let the crew plan the tide for you. A few lines save a lot of back and forth on WhatsApp.
- Your date and one backup date, in case the tide is better a day later.
- The number of adults and children, with the children's ages.
- "The sandbar is a priority" in plain words, so the stops are ordered around low water.
- Morning or afternoon preference, or "whatever fits the tide".
- Whether you need masks for everyone, and any swimmers who need a vest.
Pack sun cream that is kind to the reef, a hat, reef shoes or sandals and a dry bag for your phone. Bring a little cash for the park fee, since it is collected separately and is not part of the boat price.
The request is free and non-binding: a manager checks the boat is free on your date and confirms the final price. Then all you have to do is be at the pier on time and let the tide do the rest.
Questions and answers
Can you walk from Koh Tup to Chicken Island?
Yes, at low tide a sandbar connects Koh Tup, Chicken Island and the small Koh Mor, and you can walk along it. Around high tide the same stretch is underwater, so you wade or swim instead. Check the tide for your date before you book.
What time is the sandbar visible today?
It depends on the tide, which moves later by roughly 45 to 50 minutes each day. Look up the Krabi tide table for your date and aim for an hour or two either side of the daytime low tide. The boat crew can confirm the best window when you book.
Is the Tup Island sandbar visible at high tide?
Usually not. At high tide you see a shallow, pale stretch of water where the bar lies, but not dry sand. It is still a nice swim stop, just not a walk.
Do I need to pay a fee to visit Chicken Island and the sandbar?
The islands are inside a national park, so a park fee may be collected on the day. It is paid separately and is not included in the boat price, so carry some cash.
Is the sandbar good for children?
The shallow water is great for kids at low tide, but there is no shade and the sand gets very hot. Bring hats, water shoes and a life vest for younger children, and keep them close when the tide starts coming back.
Can a long-tail boat reach the sandbar?
Yes, a long-tail has a shallow draft and can usually anchor close to the sand. A larger catamaran anchors further out, and the crew uses the dinghy or guests swim in.
Is a half day enough for the sandbar and Chicken Island?
Yes, if the low tide falls inside your time slot. A half day covers the sandbar and a snorkel at Chicken Island comfortably, while a full day lets you add all four islands at a slower pace.
Ready to choose your boat?
Every boat page shows the routes, prices and what is included. The booking request is free: a manager checks the boat is free on your date and confirms the price.
Updated 13 November 2026. Prices can change: the boat page always shows the current price.
