Try any of the river mouths down there bound to have a kahawai or salmon. Not to sure about any other options in the south. North Is. has a lot more to offer in the way of saltwater fly like the coromandel peninsula for trevally, kingfish, kahawai and snapper if you get lucky. Depending on time of year various tuna species (albacore, bonito, yellowfin) may come into range.