UPDATE 17 MAR 2023:It appears this cache has suffered from some muggle intervention and is now located in the shelter with the information panels that provide the numbers to work out the final. If the cache is still in the shelter when the next finder goes for this cache, can they please relocate it back to the final coordinates as per the hint. If the cache cannot be found, if any future finders send me the correct final coordinates by message or email, I will give them permission to log the cache as 'Found' until I can get back out and replace the cache. Please don't log a 'Needs Maintenance' log as the grim reaper may archive it before I get the chance to replace it.
The Cape Campbell lighthouse is located on private land but permission is given to access the lighthouse. You are asked to adhere to the signs and respect the privacy of those staying at the nearby accommodation.
There is no need to be concerned with timing the tides right to attempt this cache. When placing the cache I headed out from the Parking Waypoint three hours before high tide, and high tide hit us about half way back. There are a couple of places you will have to scramble up and over a landslide caused by the earthquake, but on the main one a worn track is already starting to develop. The other will only need to be used an hour either side of high tide, if at all.
06 Feb 2023: Today we went out and checked the cache. The return trip by walking for a couple in their late 50's, mid 60's was exactly three hours. This included getting information to update the cache page as the original information panel is getting weather worn and illegible, plus additional time to have some refreshments.
There is a new information kiosk at the listed coordinates. Using the Lighthouse Timeline panel, the cache can be found at S41 4A.BCD E174 1E.FGH where:
Plans were begun to construct a lighthouse at Cape Campbell in 18BH.
Construction of this lighthouse began in 18EG.
The new light tower was lit in 190C.
The tower was converted from kerosene to electricity in 19A8.
A private road was extended to reach the lighthouse in 19D0.
F = G minus C.
Check Sum: A+B+C+D+E+F+G+H=38