Hi CWK
Been to hat yai many times to visit my friend who teaches old style muay and kk and as a port to travel further south.
There is a small thai boxing stadium there or at least there was because i went one night a few years ao. I would go to the stadium and check out the fighters and trainers and see where they train and become friendly with them. Its the best bet. Makes life a whole easier. Its what i do usually to find people to train with wherever i go in thailand outside of my home kai muay. Also you see fighters in action and you can usually tell who is well trained.
I pulled up the info for the place and its on friday nights so i would go and watch all the fights and see where people train. Its a small place so its easy to talk to people. I am hoping the info is good and current.
Niphat Songkhrao 1 Road, Soi 20
Comments: There is a medium sized boxing stadium in Hat Yai. It's not Lumphini or Ratchadamnoen but it's bigger and more authentic than the venues constructed in tourist areas just for the benefit of tourists.
The location is a Soi off Niphat Songkhrao 1 Road on the same side of the road as Jiranakorn sports stadium. Going away from central Hat Yai, it's past the sports stadium but before Big C.
Bouts are held every Friday night starting at 8pm.
It's a good night out and a unique Thai experience that every visitor to Thailand should see. The only bad thing is the old Thai habit of dual pricing. When I arrived the price was clearly advertised - Bt180. I asked (in Thai) for a Bt180 ticket but she just kept telling me "haa roy Baht" - Bt500. At first I thought she hadn't understood me but I was wrong.
The price is Bt180 for Thai men, Bt50 for Thai women and Bt500 for foreigners. The raised seating, where most people were, looked fine but I was shepherded into the ringside enclosure. This was supposedly the privilege I was entitled to for paying a lot more than everyone else but I didn't think the view was as good.
Good luck let us know if you find a good trainer or kai muay.