This cache is now part of the Saltdean Border series
Parking Co-ordinates North 50 48.858', West 000 02.008'
The cache is NOT at the published co-ordinates and you do not need to visit them to find it.
In order to find the cache you need to construct and then solve a fairly tricky Sudoku puzzle. You will need to know the rules of Sudoku and how to logically solve some simple algebra maths equations.
The co-ordinates of the cache are: North A0 BC.JKL', West 000 0D.PQR'.
The letters A, B, C, D, J, K, L, P, Q, R are all digits between 1 and 9. Any zeros are put in for you. None of the letters represent a zero.
Stage 1 - Constructing the Sudoku
To construct the Sudoku you need to find the value of the following 8 letters: A, B, C, D, E, F, G and H and then substitute the numbers for those blue letters in the following Sudoku grid.
Each of the 8 letters represents a number between 1 and 9. All the 8 numbers are different from one another. Obviously because there are 8 out of 9 there is one number missing, but some Sudoku's are like that. I said it was tricky. You should be able to deduce a couple of the letters from the fact that the cache location is less than 200 metres from the above parking co-ordinates. Then you can find the other six by solving the following six equations:
C=B+B
D=Square root of D
E=A+B
F=Square Root of E
G=Square Root of B
H=B + G
Stage 2 - Solving the Sudoku
Having substituted the blue letters for the results above you should now have a standard solvable sudoku puzzle with 30 of the 81 squares filled with numbers. Six of the other 51 squares contain the red letters J, K, L, P, Q and R. Once the puzzle is completed, you will have numbers (between 1 and 9) in each of the squares that have red letters in them. Not all these numbers are different. Substitute the red letters for those numbers in the cache co-ordinate formula and, there's the cache location.
You can check your answers for this puzzle on Geochecker.com.