Koh Phi Phi to Koh Lanta Ferry

On this hop the speedboat barely costs more than the ferry, so I'd take it unless the sea is up. Bundhaya's four boats a day are the backbone, at 09:30, 11:00, 13:00 and 15:30 for ฿700 (children ฿400) on its own site, landing 30 minutes later. Satun Pakbara and Tigerline fill the gaps on the same 30-minute run, Tigerline being the cheapest seat on 12Go at about ฿550, and Andaman Wave Master's 10:30 and PP Cabana's 10:45 add two more mid-morning.

The ferries are big, slow and steady. Chaokoh sails at 11:00 and 14:00 and Lanta Petpailin at 11:30 and 16:00, about an hour for about ฿600, with air-conditioned cabins and an open deck. On a rough morning a ferry rolls far less than a speedboat, and Petpailin's 16:00 is the last boat of the day if you want a full last morning on Phi Phi.

Most of the boats on this hop are high-season boats. Bundhaya's booking system shows four departures from mid-October through the winter and just one, the 11:00, on a June date. 12Go's June listing adds Chaokoh's ferry at 11:00 and 14:00 and some resold speedboats, but Satun Pakbara, Tigerline, Petpailin and Andaman Wave Master all drop off it. So in the rainy season I'd plan on the 11:00 and book it the day before.

September and October are the wettest months on this coast, at about 336–350 mm of rain a month at the Phuket station, and a swell can cancel the speedboat outright. If it doesn't sail, the way round is the boat to Krabi and a van down to Lanta, which takes most of a day but doesn't depend on the weather.

Every boat from Phi Phi lands at Saladan pier on Lanta's northern tip. Klong Dao beach is about 2 km away, but the island is more than 30 km long, and Long Beach, Klong Khong and Kantiang are a drive south. Tuk-tuks with sidecars wait at the pier and charge about ฿400–800 to the south of the island, and Grab barely operates, so the cheapest move is a ticket that includes the van. Bundhaya sells its speedboat with a hotel drop for about ฿845 on 12Go, about ฿100 more than the boat alone, Tigerline's speedboat and van is about ฿600, and Jijie's ferry or speedboat with a hotel shuttle is about ฿950–1,300.

Lanta is where the island hop usually turns. From 15 October to 20 May, Bundhaya's speedboat leaves Saladan at 10:30 for the Trang islands and Koh Lipe (฿1,700, about three hours), with a second boat at 12:30 from November; the Koh Lanta to Koh Lipe guide has every stop. For a flight, minivans leave hourly from about 06:00 to 16:00 for Krabi airport, about 2–2.5 hours (Koh Lanta to Krabi), and speedboats cross to Rassada pier in Phuket in about 1 hour 30 all year (Koh Lanta to Phuket).

Going back, boats leave Saladan from 08:00 (the Petpailin ferry) to 16:00 (Tigerline), with Bundhaya at 10:00, 13:00 and 15:30. My Koh Lanta to Phi Phi guide has every departure, the rainy-season boat, and how to see Phi Phi in a day from Lanta.