There's a profound thing that happens to every single person who gets in that sphere even if they don't get any samples--they come back a changed scientist."" So said geophysicist Tanya Atwater. The sphere was ""Alvin,"" the dream of Woods Hole scientists and engineers who convinced their peers and federal funding agencies to build a submarine able to withstand ocean pressures at depths of 10,000 feet and more. Alvin was launched in 1964--a seven, foot steel (not titanium) ball able to crowd one pilot and two scientists inside. The name was a joke--ostensibly honoring primemover oceanographer Allyn Vine--but in reality named for Alvin the Chipmunk, hero of a song then in the Top Ten. Over 2,000 dives later--with no casualities--Alvin has proven to be no joke. In addition to chalking up data on seafloor spreading and other traditional geological matters, Alvin made history in 1977 with the first discoveries of high temperature hydrothermal vents teeming with life. At fissures, chimneys belching black ""smoke,"" and other openings in the seafloor, sulfur-loving bacteria were able to chemically synthesize carbon in an alternate food chain that includes giant clams, mussels, sea spiders, shrimp and even exotic fish. Kaharl's account describes the findings and their implications for geological and biological history in detail, but she is marvelously human as well. There is the distinctly motley crew of the distinctly bizarre first mother ship, Lulu--a slow, ugly, unsteady, cramped, pieced-together catamaran that cradled Alvin amidships. The old hostilities and unfortunately shocking behavior toward women are also brought to light. But times have changed: today Alvin has its first woman pilot, and women scientists are frequent divers. Kaharl has some revelations about scientific behavior as well. This is no public relations job. Indeed, the book was written on a research grant and displays a scrupulous attention to detail and veracity. The science, the adventure, the personalities all make for absorbing reading.