There are a few isolated records of individual belugas reaching coastal waters of Washington, and a herd of 21 was seen several years ago during late May in Yakutat Bay, southeast Alaska. Presumably such animals are emigrants from the Cook Inlet stock, which numbers only a few hundred. Occasionally, solitary belugas or very small groups are reported along the coasts of Newfoundland, Nova Scotia, and New Brunswick, and south along the U.S. coast as far as Long Island, New York. Male white whales, which are somewhat larger than females, can grow to lengths of 5 m and weigh more than 2,000 kg. The 1.5m long newborns are generally gray or brownish.
Juveniles are gray to bluish.
After the attainment of sexual maturity, the body colour changes to all white except for the edges of the flippers and flukes, which retain dark pigment. Well-fed belugas have a lumpy appearance, with folds of fat along the sides of the body. The flippers are broad and, in adult males, curl up at the tip. The flukes of adults have a convex rear margin. There is no dorsal fin, but a low, serrated ridge is present along the midline where a fin occurs on other species.