Starting at the co-ordinates given for this cache - (You will need this as well for "Aliens are Everywhere" cache and "Aliens are Everywhere - The Planet") you will need to solve the word clue to obtain the co-ordinates for each cache using the sign.
Once you have solved the clues you can complete in any order - however this one is nearest the co-ordinates given.
Reading from the top find the first instance of each letter in the word "SPACE" - The letter's position in the word on the sign is what you're looking for.
N 51 (P-1)A.(A+C)(P-1)(S-A+P)
E 001 (P-1)(A-P).E(P-1)(A+C)
This is a gentle walk out into the Marsh landscape around the Redoubt gravel pits - Using the public footpaths only. Please do not trespass onto the Sailing / Fishing land itself.