As mentioned on the main page, the original qualifying criteria for the Explorer Challenge caches was the you needed to find caches in the same number of grid squares as the number of the Explorer map. It has been recognised that this may be prohibitive for areas with higher number maps and of course it is totally up to the owner of an Explorer Challenge to set the number of qualifying squares, one suggestion being for half of the map number for Explorer maps numbered over 250.
|From personal experience I know how time consuming trying to determine which of 600 squares of an OS map a cache qualifies for, although of course the British Grid reference is given at the top of each cache page just below the main co-ordinates shown in bold, as circled below.|
For the purposes of these challenges 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
To help those of you that want to plan your finds a number of GSAK Macros have been written which produce a web page of your finds, example output shown below.
When you have found the relevant number of 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, please check individual challenge caches for the particular requirements set by individual cache owners: