The 4 o'clock wave is a part of local lore in parts of Australia. In common with most similar lore, it serves primarily to confuse outsiders and amuse locals.
The tale is common to rural riverine areas located downstream from major dams, particularly those with rivers that have the Snowy Mountains as their source. The 4 o'clock wave is supposedly a large wave, several metres in height and created by the daily release of dam overflow, that is said to travel downriver at high speed, and to reach the location at which the tale is being told at 4 o'clock each afternoon. Surfers are often said to ride this wave for hundreds of kilometres. This apocryphal wave is the man-made equivalent of the natural, and genuine, tidal bore phenomenon.
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