<p>Long-distance migration for most species of baleen whales is poorly understood because of the practical difficulties and substantial expense involved in gathering relevant data. Presently, satellite tracking is the only method that delivers the necessary detail and quantitative data on movement patterns on far-ranging marine mammals. In this study, ARGOS satellite tags were deployed on North Atlantic sei whales (<i>Balaenoptera borealis</i>) at the Azores Islands. The results show the largescale movement potential of North Atlantic sei whales from wintering grounds to highly productive potential feeding areas in the Labrador Sea. </p>