The options

Option Duration Indicative price Good to know
Lomprayah combined bus + ferry ticket About 7h30 (departs 10am, arrives about 5:30pm) See the listing Ticket to buy at least 24h ahead; refund if cancelled for bad weather
Bus or minibus Phuket - Surat Thani / Donsak, then ferry About 8h30 per one comparison site, once a day About 600 to 900 baht for the road leg; ferry about 270 baht to US$12 to 19 Last ferry from Donsak around 6pm per one source

Prices and timetables come from comparison sites and change with the season.

Tips

  • Avoid tight connections: a delay on the road makes you miss the ferry.
  • Luggage: up to 1 m free with Lomprayah, 150 baht for 1 to 1.5 m, not allowed beyond.
  • I found no confirmed direct flight: do not count on it without checking.
  • For the airport and transfers: getting around Phuket; for another island: Phuket to Koh Samui.

FAQ

How long from Phuket to Koh Phangan?

About 7h30 with the Lomprayah combined ticket, up to 8h30 or more with road and ferry separate.

Do I need to book ahead?

Yes, the Lomprayah ticket is bought at least 24h ahead.

Can it be done in one day?

Yes, leaving in the morning; allow a margin.