The cache is not at the listed co-ordinates but it is close
by.
A = "Sea Eagle" - "Osprey"
B = 0
C = "Osprey" - "Kestrel"
D = "........Raven" - "Curlew"
E = "Osprey" - "Curlew"
F = "Osprey" - "Kestrel"
Use the above to find the final co-ordinates:-
N52 03.A B C W000 48. D E F