My newspaper ran an article about tsunamis in the Chatham Islands, and it seems that there have been 7 tsunamis that reached NZ's east coast since European settlement. Two of them hit the Chathams, but only one man lost his life.
The largest wave is alleged to be 15.3 metres, but I can't believe that as the coastal towns in the district it refers to would have been wiped out, or at least severely damaged, and as it was in 1931 I think I would have heard of it, since I spent my boyhood in the region concerned. There was certainly a big earthquake at the time. It flattened most of the town, but the consequential damage I heard about related to fire, not flood.
We have no money; we must use our brains. -Ernest Rutherford.