Spent some time near Ao Nang, Andaman Sea, Krabi Province, Thailand in November 2013. As most of coastal Thailand is overrun by tourism I took our packrafts to get away from the crowds. (Go to Myanmar/Burma if you want a last glimpse at SE Asia as it was before the economic boom.)
I suggest launching west of Ao Nang town. There are a couple of islands 400 yards off shore (depends on tides) that are worth a look at and some mangroves at the far end of the bay. Mangrove leads up to a scuba diving and fishing boat mooring area and there are a few settlements in the mangrove there. You can walk back towards Ao Nang along the beach if you want and paddle across the channel. Watch out for long tails AM and PM when they return from tourist day trips.