Hangler, the jumper is a Grey Mullet. They are more than common im Hawkes Bay waters and I suspect that your rat kingfish school is also a school of grey mullet. They grow to good size and can reach 2kgs. Most are about 1 kg. They travel up our rivers as well. In the Tukituki I have seen them as far up as Waipawa. These could be a wonderful sportfish (and eater to I suspect) but are very hard to lure into taking a hook. Some talk of taking them on breadcrusts, others on worms. In my years of fishing I have caught a handful and usually out of the blue when targetting them hasnt worked.