Rays hit the shallows in either of the sounds. Caught heaps in the grove arm last summer. Would also catch Snapper, gurnard and trevally while targeting them.
For sharks, try around the 3 fords or the mouth of the Washdyke stream (they very close to each other)… Last summer I normally got around 3-5 big sharks (combination of sevengillers and topes) in 2-4hrs over high tide there. Infact, anywhere between the mouth of the Clarence and Kekerengu River mouth would be worth a try, the places I listed have easy access.
For even bigger sharks, need to find the bronzies in the outer sounds. Can not offer much advice.
For kingfish, I would probably try off the rocks around Hori Bay, or maybe walk around the coast out of cable bay.