Puzzle Solvers Toolkit #1 Mystery Cache

The cache is not at the posted coordinates but is less than 2 miles away

This puzzle is the first in a series to highlight a tool that should be in every puzzle solvers toolkit.

FizzyCalc was written by San Francisco Bay Area geocacher and Charter Member fizzymagic to “calculate all kinds of fun things, such as distances, projections, WAAS satellite positions, coordinate checksums, and geocaching.com cache numbers and waypoint names."

You can download the Windows version here or the Mac Version here. No installation program is required. Just click on the .exe (Windows) and .app (Mac) to run the program. Although the order is the same, there is a slight difference in the tab names between the Windows and the Mac program.

This puzzle will explore a few of its most commonly used features. The puzzle begins after a brief description of each feature.

Coord Conversion - Allows for simple conversion of coordinates to various formats. It takes coordinate strings in a variety of formats and generates copy-and-paste versions of those coordinates in a variety of other formats. Geocaching recently removed this ability from their web site.

Distance - As the name implies, this feature calculates the distance and the forward/reverse bearing between two GPS points. The 3 Accuracy settings in decreasing accuracy order are High Accuracy, Great Circle, and Rhumb Line. The High Accuracy setting employs the Vincenty formula that is based on the assumption that the Earth is an oblate spheroid so the results are accurate to better than 0.03%. For short distances there is little difference in the result but when in doubt and not instructed to do otherwise, use the High Accuracy setting.

Projection - This feature is used to find the coordinates at a given distance and bearing from a Starting Point and has the same 3 Accuracy settings as Distance.

GC Waypoint Number - Geocaching uses base 31 (0-9, A-Z with the letters I, L, O, S, and U left out) to convert sequentially assigned cache numbers to GC ID’s. Mingo (GC30) is number 48 and this cache (GC68VCH) is number 5,393,709 in the Geocaching database/system. See Help Center for a more detailed explanation. You can convert from cache number to GC ID and vice versa with this feature.

Checksums - Adds up the individual digits in both the latitude and longitude and then calculates an Entire sum of all the digits. Many CO’s provide a checksum for confirmation of a puzzle solution. The digital root keeps adding the numbers until a single digit remains.

Now let’s give these features a try:

Project a waypoint from N 37 25.746 W 121 54.807 a distance of 0.25 miles at a bearing of 225 degrees. Now use the decimal portion (the digits after the “.”) of the latitude to determine WWW. For example, if the Result is N 37 25.123 W 121 55.000 then WWW would be 123.

Find the distance in feet between N 37 25.000 W 122 00.000 and N 37 24.950 W 122 00.023. Use the integer portion (the digits before the “.”) to determine XXX.

Calculate the checksum of N 37 25.700 W 121 55.300. Use the Entire sum to determine YY.

Find the cache number of Talking to the Troops (Hampshire) (GCA34E). The number is ZZZZZ.

Now convert the UTM coordinates 10S E WWWXXX N YYZZZZZ to WGS84 (N dd mm.mmm W ddd mm.mmm) to get the Final Location of the cache.

There is room for small trade and signature items. Don't forget to bring your pen.

Enjoy!

Thanks to fizzymagic for the tool and thanks to teamajk (NY) for the beta-test.

You can validate your puzzle solution with certitude.