The most common cetaceans found in Prince William Sound are killer whales, or Orcas, humpback whales, and Dall's and harbor porpoises. Other whales to look for are minke, pilot, and occasionally gray and fin whales. Two forms of Orcas are found in the Sound. They are identical in appearance, and are the same species, but they differ markedly in their behavior and feeding habits. Resident Orcas also tend to be friendly toward boats.
Transients often cruise close to shorelines, looking for unwary harbor seals and sea otters.
Humpback whales occur mostly from spring through fall in the Sound, mostly in the southwestern sector. A few non-breeders overwinter here too. Whale biologists have identified and catalogued individual humpbacks in the Sound based on the unique black and white patterns on the underside of their tail. SEA hunpback photos, right and below Dall's and harbor porpoises are found throughout much of the Sound. Dall's usually travel in groups of up to 6 - 8, and they often approach moving boats to play in its wake.