Explorer 288 Challenge Mystery Cache

This is the thirty-fourth cache within the Explorer Challenge series based on British Ordnance Survey grid squares as depicted on Explorer maps, originally conceived by PetersfieldPoodlePosse The other caches in this series are on this list.

The cache IS at the published location, which is close to the centre point of the playing area for this challenge.

To complete the challenge you need to find (or have found) a total of 288 different caches. We expect a number of you will already qualify - but how far up the league table will you get?

What is the Explorer 288 Challenge?

The cache is called the Explorer 288 Challenge because each of the 288 different caches you need to have found to qualify must be in a different British Ordnance Survey 1 kilometre grid square as depicted on the Explorer 288 Bradford & Huddersfield (East Calderdale) 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. To find out more about this and other Explorer Challenge caches, go to www.pppgeo.co.uk/explorer.html which has been created to complement the cache series.

The grids on the map "start" in the north west corner along the Aire Valley Road at SE 08000 42000...

...and "finish" in the south east near Hoylandswaine at SE 28000 04000 giving a possible thirty-nine squares (South to North) by twenty-one squares (East to West) equalling maximum possible 819 squares out of which you need to find a cache in 288 of them to qualify, a total of 35.2%. We know that some of you concern yourself with whether cache owners qualify for their own challenges so rest assured that we do, with 323 qualifying squares (as of 22nd August 2018, shown a little further below - we had 289 at the time of publishing).

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 819 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 on one of our caches. In the example below, the Grid reference is SE 18540 26779. This is the location to the nearest metre, so the 1 kilometre OS Grid square which it is located in will be SE 18 26.

It is also possible to view the location of a cache in its grid square on an OS map by scrolling down the the "For online maps..." section of the cache page and clicking the streetmap.co.uk link (as shown below).

For those of you that want automated help to plan (or prove) your finds, a GSAK macro for the various Explorer Challenges can be downloaded from here which produces a web page of your finds as well as any unfound caches in your current GSAK database selection that count toward this cache.

Here is ours showing our qualifying caches (323 as of 30th March 2019)

When you have found the 288 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 288 cache codes and names and the corresponding grid reference in your found log. e.g.
   GC3GWAY Bents tree SE 08000 37000
   GC4XGNG Marleys View SE 08000 36000;
2. Create a public bookmark list;
3. After the GSAK macro has run and displayed its output in your browser window, save the web page (as a .html file) and email it to us (flashandgrubbly [at] thomasjpitts.co.uk, replacing [at] with @);
4. Attach a screen shot of the GSAK macro generated image to your log, add it to your profile, or email it to us.
5. Use the Project GC checking system linked below.
6. Send us your "My Finds" Pocket Query and we will run the GSAK Macro for you and let you know if you qualify and if not which squares you still need to find a cache in to qualify;
7. Create a Spreadsheet grid of your finds and attach an image of it to your log.

Please include your geocaching name in any email!

The GSAK or Project GC routes are probably the easiest. If you're not familiar with GSAK and/or macros, BaSHful has very useful help page based around the Explorer 146 Challenge.

Any finds without proof of qualification will, of course, be deleted! Have fun!

Many thanks to PetersfieldPoodlePosse for producing the GSAK Macro.

Once you have completed the challenge and signed the log, you may display either of these souvenirs on your profile.

Copy this text into your profile page for the above image

<a href="http://coord.info/GC534GY"><img src="http://thomasjpitts.co.uk/geocaching/Explorer288/Explorer288Souvenir.jpg" /></a>

Copy this text into your profile page for the above image

<a href="http://coord.info/GC534GY"><img src="http://thomasjpitts.co.uk/geocaching/Explorer288/Explorer288Souvenir2019.jpg" /></a>