Hi Rob,
Waitpinga beach in Victor Harbour is famous for catching big Australian salmon. I went surf fishing there three times before but I never catch a salmon.(maybe I came at wrong timing) However there are many sand crabs and mullets around there. Goolwa beach near Victor Harbour is great for digging out fresh pipi(cockles/clams). Wish you good luck on your fishing trip there.
Cheers,
Kin