This cache is not at the posted coordinates, you may explore there on low tide but you will not find this cache by doing so!
This cache requires that you download the Geocaching Adventure Lab app from your app store. Once installed, and you are close to the starting location, open the app. The closest adventures will be displayed. You will need to choose the "Explore Narooma" Adventure Lab cache.
https://labs.geocaching.com/goto/narooma
This adventure will take you to 5 locations - each location will require a question to be answered, you can do this is any order.
At the completion of each stage the 'journal' entry will provide a clue, record these as you go or you can go back at any time to see the journal entries once the question has been successfully answered.
Once you have completed the adventure, use the 5 clues you were given in your journal entries and use these with the formula to find this bonus cache, for convenience I would suggest Mill Bay Boardwalk to be your last location.
S36 1A.BCD E150 0E.BBE
I hope you enjoy exploring beautiful Narooma and visiting a few of the locations it has to offer.