1. The cache isn't at the posted coordinates.
2. To find the coordinates of the cache, you will have to solve the puzzle below.
3. At the final location, you WILL need special equipment to get to the cache. Check the attributes.
The cache is at N51 26.Y E000 01.Z
Where,
Y = (((X * 2) + 1320) / 2) - X
Z = Y/2