As well as being a significant contributor of electricity to the national grid, the switchyard here receives the power generated from all the upper Waikato stations, and is a vital link in the transmission system that leads north and south.
Lake Whakamaru is one of the larger Waikato River reservoirs covering of 7.4 sq km. The words 'whaka' and 'maru' literally mean to give shelter to, or safeguard.
After preliminary site investigations, work began on the fourth dam in the Waikato system in 1949. The station was commissioned in 1956. Whakamaru was also the location of the control centre for the entire North Island power system until 1993.
This cache, once found, will give you a segment of the co-ordinates of a bonus cache – see the cache POWER TO THE PEOPLE (GCVXA2) for details.
This cache hunt will take you to the switchyard to pick up an answer to the final waypoint. While at the sign, listen to and feel the raw energy of this spot, transmitting the massive electrical load through the North Island. The final cache location is close to a great viewing point, make sure you have a look. Watch the kids though, there is a big drop.
At the listed waypoint look for a blue sign giving the name of the substation, and read the waypoint and freephone number (A freephone number begins with 0800)
AAA= the last 3 digits of the easting on the sign, minus 33 (note the locator is not using the standard Geocaching datum or digit format!)
BBB=the last 3 digits of the freephone number on the sign plus 4
The final cache is located at:
S 38 25.AAA
E 175 48.BBB
You are looking for a 450ml flat sistema box.
Note that at no stage of this cache hunt will you need to scale any fences, step off cleared paths, or enter any secure areas. Please also be aware that the river is not a place to swim. The water below the powerhouse is aerated, and a person is unable to float there. Do not attempt to enter the water anywhere, and watch your children close at the lookout fences.
Free Hint for all:
The final is in bush around 16 metres from the path. You should leave the path from between two rocks. Please don’t log a DNF until you have fully read the hint below.
The cache has gone missing a number of times in its long life since 2006. It will last longer for others if you hide it well, nestled between the rocks. Cover it with sticks and leaves, NOT ROCKS as they will crack the lid.
To assist with field checking of result, the checksum (total of all digits of the final waypoint) is 64