Throwing my hat at the contest - and taking a different approach:

Hagil Hornbeam's studies of the desert's energy preserving cycles have lead him to the conclusion that there is an imbalance in the desert. The only way to prove there was an imbalance was to first know what is the reason for the anomaly knaown as the Glass Ocean.

Far from being a eccentric "sandrat", Hornbeam is a genius who, after years of observation determined that there is a pattern behind the seeming chaos of the desert. Hornbeam has calculated that the energy pattern of the desert is based on two principal gyres of charged energy that orbit about each other in a seemingly chaotic pattern. The lighting strikes occur along the paths of these gyres when ever they built up significantly. It is because of these rotating energy fields that conventional compasses seem to point with no obvious direction.

Additionally, the mysterious Shale-Table Cay is a direct result of these two energy vortices. There is a balance point between these charges area that drives the finely ground sand away, exposing an underlaying rocky substrate. It appears and disappears as the storms wax and wane but remains as elusive to locate as the glass deposits that so many seek.

Horbeam has mapped these patterns and created a device, an instrument, to track the locations of the energy gyres, and when exposed, the current sand clear location, or Shale-Table Cay. The device was constructed out of carefully selected and harvested rose coloured glass slabs from the Glass Ocean itself, one of the few material able to withstand the wind-born sand for long periods. By rotating the calibrated disks within disks to track the appropriate date, Hornbeam can compensate for the distortion on compasses and determine his true headings.

It was only because of recent failures of his device that he has come to realize that the calculations he had based it on have changed, confirming that the imbalance he has been trying to convince other of is real.

Attached is the device (or at least a diagram of the device, drawn in Inkscape) Once in it "home" state and once adjusted to a particular date. The two Fibonacci spirals depict the location of the energy gyres and the third point of the equilateral triangle, the possible location of the Cay.

The device is used by aligning one mark with Copperhead Rock, and a second mark due east from there, on an appropriately scaled map.

I plan to draw that map/diagram (on suitable parchment) used to design this device, showing the general outer region of the area and the ocean, and place the device on it in the appropriate spot, made to look like thick slabs of semi-distorting rose glass, with the markings engraved in it.

The outer area of the map will be covered with some of Hornbeam's initial diagrams, calculations, and notes in his own coded shorthand...

-Rob (wow my fingers hurt from typing) A>