Dive through the 'œlayers' of the sea with world-renowned shark experts Ron and Valerie Taylor'”from the sunlit zone through the twilight zone, until finally reaching the uncharted abyss. Visit the seabed to find out more about the plants, animals, and ghostly shipwrecks that can be found there. Along the way, peer through diecut portholes inside the Titanic, lift the transparent pages to reveal the inside of a submarine, discover what goes on inside an undersea laboratory, and consider all of the unknowns that wait below in the mysterious darkness of the unexplored depths.