A vivid, up-to-date tour of the Earth's last frontier, a remote and mysterious realm that nonetheless lies close to the heart of even the most land-locked reader. The sea covers seven-tenths of the Earth, but we have mapped only a small percentage of it. The sea contains millions of species of animals and plants, but we have identified only a few thousand of them. The sea controls our planet's climate, but we do not really understand how. The sea...