Whether diving off docks, cannonballing into lakes or leaping off the high board, there’s nothing quite like the joy of jumping into water. Olympic divers turned this natural act into a sophisticated science, with the goal of making a splash as small as possible. But another sport looks for just the opposite: the extreme maximum splash, one as high, wide and loud as possible. Welcome to the world of “manu jumping.” Although not a familiar term in the United States, manu jumping is beloved...