"Delta Zulu 1, Golf Charlie 58923, approaching DZ, ETA 4 minutes, over."
"Golf Charlie 58923, Delta Zulu 1, roger, wind is zero, call when overhead, over."
"Delta Zulu 1, Golf Charlie 58923, overhead drop zone in 3…2…1… package away, over."
[Delta Zulu 1] [click]
"Delta Zulu 1, Golf Charlie 58923, some information for you, over."
[Delta Zulu 1] "Go ahead, over."
"Delta Zulu 1, Golf Charlie 58923, Cache dropped overhead N50° 59.709' W001° 25.133', flying straight and level at 3000 metres altitude, speed 116kts (60m/s), heading 125 degrees magnetic, deviation zero, variation 3 degrees west, assume g = 9.81m/s^2 and air resistance is negligible (ie. zero), over."
"Golf Charlie 58923, all received and understood, I’m on my way, Delta Zulu 1 out"…
As the aircraft disappears in to the morning murk, your eye briefly catches a glint of the tumbling object before it too fades into the distance. You sketch out the scenario in your notebook and, using the above information, calculate bearing and range for where the cache has fallen to the ground. A quick plot on the map and you eagerly set off to make the find.
You’re looking for a small clip-lock Sistema (containing a logbook and pencil) which landed not at, but within a 2-mile radius of, the published co-ordinates.
There are three mementos in the cache, one each to take away for 1st, 2nd and 3rd to find 
.
The geochecker will let you know if you are within +/-10m (and also some information on parking and even an extra hint of where to look at GZ 
).
Edit (15th July 2014): Based on some earlier logs, the geochecker now includes a photo of GZ which should help with the find
