This hike will take you along the boundary between the Crystal Cove State Park and Laguna Coast Wilderness Park.
Once you reach GZ, take care to not get bitten by a venomous animal by first visually checking where you are about to reach your hand into. Don't make this an actual dead man's tomb, please.
Once you find and open the vault (metal container), you will need to figure out how to open the wood coffin (log container) in order to sign the log. Don't force it. The coffin should open easily if you're doing it correctly. Once opened and signed, please place the log back into the coffin. Make sure to match the numbers on the coffin in order to close it correctly.
BYOP. Feel free to leave swag in the vault, but not in the coffin.