This field guide is designed to permit observers to identify the cetaceans (whales, dolphins, and porpoises) they see in western North Atlantic, including the Caribbean Sea, the Gulf of Mexico, and the coastal waters of the United States and Canada. The animals described are not grouped by scientific relationships but by similarities in appearance in the field. Photographs of the animals in their natural environment are the main aids to identification. A dichotomized key is provided to aid in identification of stranded cetaceans and appendices describe how and to whom to report data in live and dead cetaceans. (Author/CP)