Jeff MacKinnon's team battles thick kelp, brutal currents, and a looming storm while searching Scatarie Island's coast. Just as the storm hits, they make a crucial discovery--a clue that could lead to the long-lost wrecks and hidden treasure.

Following the trail of a cache of precious gemstones, Jeff and the team move further beyond the breakers, in search of The Neptune. With stormy weather closing in, a puzzling find may lead them one step closer to a privateer's long-lost treasure.