If you wanted to actually target Stingrays, I’d probably use a wire trace and heavy shockleader. My shark traces have about 80 – 90cm of 250lb Mono, and around a 30cm length of really heavy plastic coated wire. I had been using around 8/0 – 10/0 stainless steel hooks, but I’ve made a few traces up with 10/0 recurve/circle type hooks. Also if you make the trace so it has the bait sort of sitting on the ocean floor, and use a whole mullet or whole crab as bait.
Even if the trace might be a bit overkill, at least it’s still in good condition after hooking a couple sharks/rays. Also it’s important to use plastic coated wire, and use either heat shrink or electrical tape over any crimps, and even some electrical tape up the hook to about the barb, as sharks can actually detect the metal, and can put them off.
Haven’t been fishing around lyttelton for years now. Wasn’t sure if there was anywhere suitable to fish from. I remember the last time I fished there, I caught loads of small mullet, but it wasn’t really off any rocks or a wharf.