Explorer 145 Challenge Mystery Cache

This is the third cache in the Explorer Challenge series, originally conceived by PetersfieldPoodlePosse, and based upon British Ordnance Survey grid squares as depicted on Explorer maps.

The cache is not at the published location which is the centre point of the playing area for this Challenge. But there is no puzzle - the co-ordinates for the physical cache can be found in the Waypoints section below. Please approach the cache from the North or West. DO NOT try accessing it from the A31 - it is very very busy and it is impossible to park near the start of the footpaths.

To complete the challenge you need to find (or have found) a total of 145 different caches. I expect a fair number of you will already qualify - so who will be the first to the cache?

What is the Explorer 145 Challenge?

	The cache is called the Explorer 145 Challenge because each of the 145 different caches you need to have found to qualify must be in a different British Ordnance Survey grid square as depicted on the Explorer 145 Guildford & Farnham map.
	The caches can be of any type, previous finds qualify (including those finds now archived and events attended (even if you were the host)), in fact just about any cache other than those you have placed yourself can be counted.

The grids on the map "start" in the north west corner near Blackbushe Airport, Hampshire at
SU 80000 60000

and "finish" near Ewhurst, Surrey at TQ 10000 40000, giving a possible twenty (SU60 to SU40) northing squares and thirty (SU80 to TQ10) easting squares. 600 squares in total in which you need to find a cache in 145 different squares to qualify.

For the purposes of this challenge the published co-ordinates of all caches, including Unknown/Mystery and Multi caches are those that are to be used when determining which square a cache counts towards.

So how do I know which of the 600 grid squares on the OS map my cache find is in? Well, the British OS Grid reference is given at the top of each cache page just below the main co-ordinates, as circled in red below. Or if you click on the streetmap.co.uk link in the "For online maps..." section of the cache page, this will show the location of the cache in its grid square on an OS map.

For those of you that want automated help to plan (or prove) your finds a GSAK Macro has been written which produces a web page of your finds and any unfound caches in your current GSAK database selection that count toward this cache.

When you have found the 145 caches, you need to provide proof of that fact to be eligible to claim a find on the cache; this can be via one of any number of different methods you may have available:

1. List the 145 cache codes and names and the corresponding grid reference in your found log. e.g.
   GCV974 Gostrey Meadow Micro SU 84000 46000
   GC22K57 Elizabeth R? SU 93000 51000
2. Create a public bookmark list
3. Create a Spreadsheet grid of your finds and attach an image of it to your log.
4. Attach the GSAK Macro generated image to your log, add it to your profile, or email it to me

A League Table of squares filled by finders is shown below: (those in grey have not found the cache as yet)

Thanks to PetersfieldPoodlePosse for graciously allowing me to re-use his excellent Explorer Challenge concept and for producing the GSAK Macro.