An old sea chest, a letter, a list of shipwrecks and a riddle âe¦ crack the code and find the sunken treasure with this underwater adventure. âeoeDear Duncan A small fortune in gold could be yours âe" if you are smart enough to find it. I'm leaving a list of shipwrecks and a riddle âe" the rest is up to you...âe Uncle Joeâe Dive in and take the challenge with Duncan Cameron to search for sunken treasure. There are real shipwrecks to explore, secrets to unravel, and a mystery to solve, plus flaps to unfold, charts to read, a compass, pieces of eight, maps, and much more to help your quest. Can YOU spot the clues along the way âe" and crack Uncle Joeâe(tm)s riddle?