Loh Dalam Bay and Tonsai: The Two Sides of Phi Phi Don

Phi Phi Don is a single island pinched into two halves by a low sandy isthmus, with a bay on each side. Loh Dalam Bay is the wide, shallow crescent on one side; Tonsai Bay, which holds the island's main pier, is on the other. Which one your boat uses on the day depends on the weather, and understanding that difference is most of what you need to make sense of a Phi Phi day trip.

Where the bay sits on Phi Phi Don

Phi Phi Don is the only inhabited island in the group, about 8 km long and 3.5 km wide, covering 10.27 km² (Wikipedia, 2026). Two tall limestone ridges make up most of it, and between them runs a strip of flat sand carrying the village. That strip is narrow and very low — Wikipedia records the isthmus as rising less than two metres above sea level — which is why you can stand in the middle of the island and see water on both sides at once. Loh Dalam Bay is the bay on the northern side of that strip. It is broad, shallow and sandy, and at low water the sea pulls back a long way, leaving a wide flat beach where there had been swimming depth a few hours earlier. Tonsai Bay faces the other way, and it is where the boats go: Wikipedia notes that Tonsai holds a deep-water government pier, completed in late 2009. Walking from one bay to the other takes a few minutes on flat ground. That geography is the practical point, and it is the part most itineraries leave out. Two bays sit back to back, a short walk apart, each open to weather from a different direction. Skippers choose between them on the day according to conditions, so a tour that simply says it “stops at Phi Phi Don” may mean either one. Knowing there are two, and that they behave differently, is what stops that vagueness from being a surprise.

The two bays compared

The pair look much alike on a map and behave quite differently in practice. This is the comparison a day visitor actually needs.

	Loh Dalam Bay	Tonsai Bay
Position	North side of the isthmus	South side of the isthmus
Character	Wide, shallow swimming crescent	Working bay and arrival point
Main pier	No	Yes — deep-water pier, completed late 2009 (Wikipedia, 2026)
Effect of the tide	Pronounced; the water retreats a long way at low tide	Less noticeable; depth is held at the pier
Usual traffic	Swimmers, kayaks, small craft	Ferries, longtails, tour boats
Walk to the other bay	A few minutes across the isthmus	A few minutes across the isthmus

Neither bay outranks the other; they do different jobs. If your day includes time ashore on Phi Phi Don you will probably see both, because crossing between them is a short walk rather than a journey. The useful habit is to treat the pair as one place with two faces, and to let the crew tell you on the morning which face you are getting.

The six islands, and which ones a day tour reaches

“The Phi Phi Islands” names a group of six, not one place, and a good deal of confusion starts there. Wikipedia (2026) lists them as Ko Phi Phi Don, Ko Phi Phi Le, Ko Mai Phai, Ko Yung, Ko Bida Nok and Ko Bida Nai, with a combined area of 12.06 km². All six sit inside Hat Noppharat Thara–Mu Ko Phi Phi National Park. Phi Phi Don is the one with the village, the pier and the two bays. Ko Phi Phi Le, at roughly 1.27 km², is uninhabited: it holds Maya Bay, Pileh Lagoon and the Viking Cave, and it is the island most day-trip photographs come from. Ko Mai Phai is better known as Bamboo Island, a small sandy stop to the north. Ko Yung is the rocky one often called Mosquito Island. Ko Bida Nok and Ko Bida Nai are limestone outcrops to the south, used mainly by divers. A single day from Phuket does not reach all six, and an itinerary promising otherwise is worth questioning. Two Sea Tour's day runs to Phi Phi Le for Maya Bay and Pileh Lagoon, passes the Viking Cave and Monkey Beach from the water, stops twice for snorkelling, and finishes with a swim at Bamboo. The Bida outcrops are a diving destination rather than a day-trip stop, and Two Sea Tour does not visit them. Two Sea Tour also does not run to the Similan Islands, which are too far north for a day return from Phuket.

What a day from Phuket actually involves

The sequence below is Two Sea Tour's Phi Phi Island Speedboat Tour as it runs, with times from the published schedule. The early start is deliberate rather than incidental: it puts the boat at the main stops ahead of the crowds rather than alongside them.

1. Hotel pickup at roughly 5:00 AM, with the exact time emailed at midday the day before.
2. Light breakfast at Boat Lagoon Marina before boarding.
3. Depart the marina at 6:00 AM, with a maximum of 18 adults aboard and 14 on an average day.
4. Reach Maya Bay on Phi Phi Le as the first stop of the morning.
5. Swim at Pileh Lagoon, then pass the Viking Cave and Monkey Beach from the boat.
6. Stop twice for snorkelling, with gear provided.
7. Eat a Thai lunch at a beach restaurant, ahead of the midday rise in boat traffic.
8. Finish with a swim at Bamboo Beach before turning for Phuket.
9. Arrive back at your hotel at roughly 3:00 PM, seven to eight hours after leaving the marina.

Dolphins are sometimes seen on the crossing. They are not guaranteed, and no honest operator will promise them — if you are lucky, you will see them, and if you are not, the day is unchanged in every other respect.

What changes as the monsoon ends

Phuket's high season runs from November to April; the southwest monsoon covers roughly May to October. The turn between the two is happening now, and it shows up in search behaviour as clearly as it shows up in the weather. Measured on 11 October 2026: Google Trends for Thailand shows interest in “phi phi” climbing from 41 in mid-October last year to 100 by mid-November, roughly doubling across the same few weeks we are in at the moment. In Australia, one of the larger source markets for Phuket, Google Trends interest in “phuket” has risen from 64 on 20 September 2026 to 81 on 11 October 2026. For a visitor the consequences are practical rather than abstract. Sea conditions generally settle through November, which widens the choice of stops a skipper can make on any given day. Boats fill earlier in the season, so the gap between deciding and booking narrows — in December and January it can close altogether. And because the two bays on Phi Phi Don face opposite ways, the sheltered side changes with the wind, which is the honest reason a careful operator will not promise you one specific bay weeks in advance. A tour that does make that promise is either getting lucky or not thinking about it.

The Phi Phi Islands: what you need to know before you go

If you read nothing else here, these are the points that change how a day actually goes. The islands sit inside a national park and entrance fees apply. On a Two Sea Tour day those fees are already inside the price rather than collected from you on the water, which matters mainly because it removes one thing to carry cash for. Phi Phi Don has around 2,500 residents (Wikipedia, 2018 figure), so the village is genuinely small and feels busiest in the middle of the day — another argument for an early boat rather than a late one. There is no road crossing from Phuket and no airport on the island: every arrival is by sea, which is why departure times are early and fixed rather than flexible. Tides matter more here than visitors expect. The northern bay is shallow enough that what you see at nine in the morning is not what you would see at three in the afternoon, so photographs taken at different states of the tide can look like different places. Bring something to cover your shoulders for the open crossing, and expect the boat to be wet. Two Sea Tour's published rates for the Phi Phi Island Speedboat Tour are ฿4,300 for an adult, ฿2,750 for a child aged 4–12 and ฿2,000 for an additional person aged 12 and over. Cancellation is free up to 24 hours before the tour, which is worth knowing in a season when the weather can change a plan. Two questions are worth asking any operator before you book, whoever you go with. The first is how many people will be on the boat: the difference between fourteen and forty is the difference between stepping straight off at a stop and queuing to do it. Two Sea Tour caps the day at 18 adults and averages 14. The second is what time the boat leaves the marina, because on a route where every operator visits the same handful of places, the departure time decides whether you arrive ahead of the crowds or among them.

Getting to Loh Dalam Bay from Phuket

There is no bridge and no airstrip, so the crossing is by boat from Phuket or Krabi. Ferries run to the Tonsai pier and take the longest. A speedboat day tour is quicker, and more usefully it is built around the stops rather than around the arrival — the point is the water between the islands, not the pier at the end of it. Two Sea Tour departs from Boat Lagoon Marina on Phuket's east coast, with free hotel pickup inside the published Phuket zone and a 1,000 baht return surcharge per vehicle for addresses outside it. For the full hour-by-hour shape of the day, our account of what a Phi Phi speedboat day looks like covers it in detail, and our guide to choosing a Phi Phi speedboat tour from Phuket compares the options against each other. For what is worth doing once you are ashore, see ten Phi Phi island activities worth the day. If you are weighing a day that pairs Phi Phi with closer islands, the Phi Phi and Khai Islands combination is the other shape the day can take. General background on the island group is on Wikipedia's Phi Phi Islands page.

Booking a day from Phuket

Two Sea Tour has run small-group speedboat days out of Phuket for over fifteen years, carrying a maximum of 18 adults and an average of 14. If you would like to see Loh Dalam Bay, Tonsai and the rest of the group on a boat that leaves early and stays small, the Phi Phi Island Speedboat Tour is the day to look at. Questions are welcome before you book — call +66 81 787 7702 or message +66 62 979 9974 on WhatsApp, and someone who has actually been on the water will answer.