As Rai Lay is a peninsula surrounded by ocean and mountains, final access can only be by boat. Long-tails depart from Ao Nang 10 minutes, 100 baht/person, minimum 8 people and Krabi 30 minutes on demand, making those towns the gateways to Rai Leh. It's also possible to access Rai Leh via regular ferries that run between Ko Lanta, Ko Phi Phi, and Phuket Town from Rassada Pier more frequent in the November-May dry season; times available from local travel agents, or check (http://koh-lanta-island.org/traffic/ferryschedule.htm online ferry schedules).
The Krabi, Phuket, Ko Lanta and Ko Phi Phi articles have information on reaching the gateways to Rai Leh from throughout Thailand. From Bangkok there are flights to Krabi and Phuket, direct bus services, and trains to Surat Thani with onward connections by bus.
NB: If departing from Ao Nang, be aware that you're expected to walk out several metres into the surf before getting on a boat depending on the tide. It might be best to change into clothes suitable for getting wet, or at the very least be sure you don't have more luggage than you can carry a few metres into the ocean.
