Build boat and title

I tried to post this in the Ask The Lawyer section, but there was no option to post when I clicked the sticky's link to do.so.

I want to build a simple, cheap, camping-style boat. Basically a barge with a cover and a small indoor area. 3 meters by 9 meters total size. Probably cost less than 30k Baht in materials.

It is NOT being built for resale, only my use.

So how do I find the laws pertaining to such craft? Building codes (if any), inspections (if any), how to register and title, etc?

I have gotten much conflicting advice - pleasure craft are not allowed (yeah, right!), no registration under a certain tonnage, licensing includes fishing rights, must have a work permit to build it myself, etc.

I realize TiT and there may not be a universal code - where I build and launch and moor I may have to work with local officials. Every place I visit the same. Etc. But surely there is title rights and some formality or Phuket would not be so organized. Thailand is actively encouraging boating tourists and residents according to a newspaper article in Phuket.

I am in Bangkok, will probably build in Rayong at a small boat yard (Ban Pae) or farm near there. I plan to.never visit Phuket anyway, this is just a pleasure craft for the upper gulf.

Thanks!