This new field guide is a complete & convenient reference to every species of cetacean pinniped & sirenian in the world along with the Marine & Sea Otters & the Polar Bear. Every species is illustrated with magnificent colour paintings & a stunning collection of photographs chosen to illustrate the key field marks which can be used to separate each species in the field. The authors unique depth of experience & knowledge coupled with the artists unrivalled skill have come together to produce a neat practical field guide that will enable any observer to quickly identify any mammals they may encounter at sea.