Flights & getting there
There’s no official public transport to the Similans. Theoretically, independent travellers can book return speedboat transfers (2000B, 1½ hours each way) with a Khao Lak day-trip operator, though they discourage independent travel. Most will collect you from Hat Khao Lak, but if you book through the national park you’ll have to find your own way to the office in Thap Lamu and wait for a pier transfer.
Dive centres and tour agents in Hat Khao Lak and Phuket book day/overnight tours (from 4900/8500B), dive trips (three-day liveaboards from 10,500B to 19,000B) and multiday trips including park transport, food and lodging, which cost little more than what you’d pay getting to and staying on the islands independently.