Fantastic little trip - we caught a longboat for 1500 Baht return for 8 adults from Ao Nang beach to Railays beach. Negotiated it with a lady standing at the top of the break wall. It takes about 15 mins via boat then about a 20 min walk. You can pull yourself up about 200m of cliff face to see the lookout Aswell. Very cool swimming under the cliff faces. Also has two fertility shrines with a lot of hand carved penis statues.