Sound travels fast in the sea, three times faster than in the air, and so do stories. Some stories go around the world underwater, without being heard above it. Unless they need to be. The dolphin pod from the shallow, warm gulf of the green ocean (the sea men call Atlantic) like to sing about Chax. Chax has led them well. His reputation is known. His exploits are part of the pod's long song, the chirping song that tells the pod's story. The song reminds the oldest dolphins of what has come before, and informs the newest ones. Dolphins from other pods - even some birds - know parts of it. Chax has been everywhere, and done other exploits, but this was his first. The song tells how Chax kept sharks from eating men that fell from the sky. This was long before he became a leader of the pod. Every dolphin in the pod can sing parts of that song, but no one knows it all, except Chax. He sang it the first time, tired and amazed to be alive as he was. A few terns had been there and added details. Part of it became part of the pod's song. When Chax became leader, it became more important, but it was already a good part. Chax protected the men, so the story goes, because he was offered the opportunity, and because he admired one of them. Some men are admirable. Chax had been swimming out from the pod on a hot day in spring. The pod was resting, feeding on mullet - slender, silver, oily, tasty, easily excitable fish. Mullet thrive in the warm water along the edges of what men call the Gulf of Mexico. Chax heard about the men from terns, who had heard from whales. The leaders had said Chax could swim away from the pod if he wished. As a full-grown dolphin, growing into his place, he was ready. Whales had seen the men fall. After Chax found the whales, he was guided to the men by a noise the whales told him about. He swam until he heard it. Eventually it stopped, but he found the bubble the men were in anyway. He asked gulls and terns and pelicans, and listened. Sharks had found the men too. By the time Chax arrived, several had gathered. Chax scanned the men with sounds he directed at them. From the echoes that came back, he could tell that the men rode what was mostly a bubble, covered with skin. Dolphins can send sound through the water, out of their soft foreheads - though it takes effort - and they can learn much from the echoes that bounce back. Much. Sound is intense under water, and full of information. Want an overview? Read on: Dolphins have helped swimmers in trouble for as long as people have shared the ocean with them. Despite reasons not to like us, it seems they do. Accounts of the human-dolphin relationship are found in the legends and art of antiquity, and in tomorrow's cable news cycle. Yet much remains a mystery. Chax: A Dolphin's Song, considers many of those things, sometimes from the dolphin's perspective. It's not just a dolphin story, however. One reader described it as "southern gothic gone to sea." One "hero" is Chax, who leads a pod of bottlenose dolphins in the Gulf of Mexico. With help from his friends. Chax is a superb listener. Popper, a young dolphin learning his place in the pod, helps too. The reader sees and hears what the dolphins do, and hears them "talk" to each other. Kimberly Barone, a bright young marine biologist, studies dolphins and the deteriorating ocean environment with passion, even if her boss and former professor has lost focus. The boat that serves as their base is captained by a former Coast Guard rescue diver. Captain Pete Gordon is as passionate about the ocean as Kimberly, and sees so much more in her than the jaded professor. A Navy submarine is in Chax's neighborhood, paying attention, especially Sonar Technician 1st Class Opie Simcox, who goes above and beyond. Smooth, talented, amoral Claiborne Chandler's choices have led him from privilege to piracy. He is no hero. Dodging responsibility has brought him here. Yet even Claiborne knows dolphins are spe