For the Andaman Coast, quite a lot of aerial photographs are available from Bing. I started tracing from them some days ago, and meanwhile covered the region from Phuket to just South of Ranong, and from Phuket to Ao Luk (East of Pang Nga).
After downloading 1.5 GB of OSM data (oh dear, why do I have to download the file of whole Asia?), I created a map which I want to share. You can download it from:
http://www.berniesmaps.de/Thailand.img
This map covers the area from 5 degrees North to 21 degrees North, and from 97 degrees East to 106 degrees East (i.e. whole Thailand plus "bordering" regions). I hope you find it useful and will be encouraged to add more data and do some corrections.