Top-secret wartime experiments were conducted off the coast of Auckland to perfect a tidal wave bomb. According to this New Zealand News report a series of underwater explosions triggered mini-tidal waves at Whangaparaoa in 1944 and 1945. The Weekend Herald reported
The experiments involved laying a pattern of explosives underwater to create a tsunami. Small-scale explosions were carried out in the Pacific and off Whangaparaoa, which at the time was controlled by the Army.
It is unclear what happened to Project Seal once the final report was forwarded to Wellington Defence Headquarters late in the 1940s.
Details of the tsunami bomb, known as Project Seal and stamped “top secret,” show the US and British military were eager for Seal to be developed in the post-war years too. Though high-ranking New Zealand and US officers spoke out in support of the research, no details of it were released because the work was on-going.