Kata beach fresh seafood market is an excellent place to go when you are looking for some fresh cheap seafood that you are going to cook or BBQ yourself. I love going to open markets you can find just about any type of Thai cuisine ingredient and of course fresh seafood.
The seafood is as fresh as it gets, most off the seafood is only hours from either the ocean or farm, not days ago like seafood you might find in some of the big grocery chains. If you want to save a ton of cash on your food bill the open markets are the deal, I frequent the Kata Beach market all the time partly because my condominium at the Aspasia Phuket is only a few minutes away from the market so I am a regular customer. We just load up the car with plenty of fresh seafood, veggies and fruit to last the week, although last year I had to buy an extra refrigerator to help with the storage, but it was well worth it considering how much cash we can save by cooking it ourselves.
I learned to cook quite a few Thai dishes over at Pat's Home Thai cooking school and that was a really big help. If you're wondering where all the resorts and restaurants get their fresh food just go to the open market I am constantly running into chefs from various resorts picking up fresh ingredients for their restaurant menus.
Here is a short video clip of the seafood section at the Kata Beach open market, keep in mind this is only a small selection compared to some other Phuket markets that I have been to. Once you are in Phuket go to the market they truly are a unique experience and a whole lot of fun.