THE CACHE IS NOT AT THE POSTED COORDINATES.
To solve this bonus cache puzzle, you must first complete the Adventure Lab "Welcome to Atlantic Beach." The coodinates will be given to you at the end of the Adventure Lab.
Adventure Labs are Geocaching's newest game. It is played on your smart phone through the Adventure Lab app. Download the app and search nearby for "Welcome to Atlantic Beach" adventure.
The cache is right off the trail, so no need to bushwack.