It is a competitive event, without an overnight camp (although teams must be equipped to bivouac if the conditions are severe enough to warrant it).

The hike usually takes place on the second or third Saturday in April, but this may vary depending on the timing of Easter.

Originally, based around the North and West of Reading, the hike gets its name from the three large water towers that were passed.

In the 1980s, the route was significantly altered to include more rural paths in West Berkshire and South Oxfordshire.

Officially not against the hike rules at the time, one team on the 2002 Junior Event swam across the River Thames during the race after finding themselves several miles up stream of the nearest bridge.