High school students can read about the advances in marine science until their eyes glaze over, but it is the people and the personalities behind deep sea exploration that grab young folks' attention. This book, part of the "Milestones in Discovery and Invention" series, profiles ten scientists, plus their accomplishments and research. Scotsman Wyville Thomson, expected to become a medical doctor like his father, was intrigued by the theory that nothing lived in the deep sea. He persuaded the Royal Navy to give him The Challenger, a small war ship, and had it remodeled into a research vessel from which he conducted his pioneering research in the 1800s—the same decade in which Charles Darwin and Jules Verne were publishing. William Beebe, born in 1877, spent a young naturalist's childhood in Orange, New Jersey, collecting birds' nests, insects, and fossils. He grew up to attend Columbia University, then led scientific expeditions all over the world. His dream of deep sea exploration, along with advice from Theodore Roosevelt, resulted in his designing the Bathysphere, which traveled a mile and a half down into the sea. Swiss scientist/engineer Jacques Piccard improved on this and developed the bathyscaphe, another deep sea exploration vessel. Bruce Charles Heezen and Maria Tharp worked to map the ocean floor. Harry Hammond Hess's theory about seafloor spreading explains how the earth's crust is created and destroyed beneath the ocean floor. Henry Stommel's research worked out the ocean's major surface, as well as deep water currents. Allyn Vine's name is forever linked with the human-operated submersible, Alvin, which is famous for exploring the Titanic. RobertBallard is known throughout the world as an undersea explorer. John Delaney is an expert in underwater—seafloor—volcanoes and how they create new crust and support life. Cindy Lee Van Dover, dubbed "not college material" as she was growing up, became the only scientist and woman ever certified to pilot the Alvin. Her research revealed that undersea vents give off a natural glow—named "the Van Dover Glow"—and that animals living near these deepwater vents can detect this glow. Each chapter includes a scientist's biography, their research, other researchers with whom they collaborated, a chronology, and list of further readings. As the quote at the beginning of the book from Jules Verne's character Professor Aronnax states: "The deepest parts of the ocean are unknown to us. What goes on in these remote abysses…we can hardly imagine." This full title goes a long way toward introducing scientists, with their struggles and achievements, who have helped our imagining. The book contains an extensive index, a glossary, and a general chronology. It is a must for high school marine science classrooms or libraries.