In order to find the hidden cache you will need to complete the Riverhead Adventure Lab Cache first.
Within the journal for each adventure lab there is another question , answer these and convert the letters below to numbers you find and work out the Mathematics below and its another smiley to add to your collection !!!
!!! Happy Caching !!!
N51° (A-F) (B+C) . (D-J) (G+F+H) (E+C)
E000° (J-E) (A-H) . (G-F) (B-G-C) (C+F)
Have fun and take care crossing thr roads !!