Over summer, a strange phenomenon plays out along New Zealand’s waterholes. Bridges, wharfs, cliffs and swimming pools throng with people readying to leap. Jumpers launch into the air, twist themselves into a v-shape – bums down, limbs akimbo – until they hit the surface, forcing water upwards in an almighty splash. The bigger the splash and the more inventive the jump, the louder the cheers. These are the “manu” jumpers – people who get a thrill and sometimes compete – in the sport of manu, a unique New Zealand diving technique similar to a bomb, developed by Māori and Pasifika