Hey mate, shame you're not staying a bit longer, I'm planning to be there from about 10 March.
I usually stay down the other end of the island, towards Rawai, Kata, Karon so I'm not so sure about Patong spearing locations but get in contact with Tong. Hes a good guy I met in Vietnam about 10 years ago, from Holland but lives in Phuket now, speaks perfect english and a keen spearo. He'll be able to take you to some decent spots to dive and restaurants to cook your catch.
I'll PM you his number.
Cam
Hi, I am in Phuket.
Can you give me Tongs number please.