I lived in Phuket for ten years and would often go to our local beach (Rawai) to watch the boat-builders. Their primary tool is the adze, supplemented with a large, portable, circular-saw if they could get a generator to run the thing.
The planks were finished to quite a decent standard, and grown-timber frames were added after the planking - not unlike traditional Shetland craftsmanship.
As Rich points out, if not regularly painted, the timbers soon get to look shabby.
Geoff,
I've moved and now I'm about 800 miles from Phuket,
Thailand,