There are four stages before getting to the cache.
First Stage: Co-ords are those already shown for start of this trail.
Take information from site as described below
N 50° 49.---
Add the digits of Truro miles minus 1, deduct 2nd number from 1st of Swansea miles , last number of New York miles.
W 004° --.00- 1st two numbers of Paris miles, last number of Exeter miles
Second Stage: look for 6 figure phone number (excluding std ) = ABCDEF
N 50° 49.--- (A+D)E,D W 004° --.--- C,D.(A+C)(B+D)C
Third Stage: Year Gurney was born = ABCD
N 50° 49.--- B(C-D)(Ax2) W 004° 33.--- A(D-A)C
PLEASE USE THIRD STAGE INFORMATION AGAIN TO FIND THE CACHE WITH THIS FORMULA as the next waypoint is currently unavailable due to work being done on lock gates
N50°49. (B-2) D (A-A) W004°33. (B-D) A (C-4)
Fourth Stage: Look for phone number ABAACDBEDAD This will take you to the cache N 50° 49.--- (B+D)B,A W 004° 33.--- (B+C)C(B+D)
PLEASE NOTE. Final location may be hazardous for young children - needs great care at latest stage of search