The White Horse which dominates the side of the hill behind Waimate is well worth visiting. You can walk up via the walkway or drive via Mill Rd The given coordinates will take you to memorial plagues where you can gather the information to find the final cache which is within easy walking distance.
The final cache is at S 44 44.ABB E 171 00.CDE where
A = number letters in male christian name
B = number times horse/horses mentioned
C = Number of words in 4th line of top plaque
D = 3rd digit - 1st digit of date
E = Total letters on top line bottom plague divided by 5
A+B+C+D+E= 20
The cache is a 300 ml white plastic container with logbook and pencil and with room for small swaps.