At the posted coordinates find a sign which has a latitude and longitude on it.
This is -33.ABCDEFG 151.HIJKLMN
Now move to S33 32.8BN E151 13.97K
You can see the cache location from here. At this waypoint find the gun emplacement.
What is the size of the gun that was here (in inches)? This is P.
The cache is located atS33 3F.(G+E)(J+L+M)(K+F) E151 1P.(L+M+P)(P+L)(M+B)