The Sei Whale (pronounced /ˈseɪ/ or /ˈsaɪ/), Balaenoptera borealis, is a baleen whale, the third-largest rorqual after the Blue Whale and the Fin Whale. It can be found worldwide in all oceans and adjoining seas, and prefers deep off-shore waters. It tends to avoid polar and tropical waters and semi-enclosed bodies of water. The Sei Whale migrates annually from cool and subpolar waters in summer to temperate and subtropical waters for winter, although in most areas...