POSSESSION BAY — Languid and liquid as the swells it surfs, the gray whale gives a mighty blow then arcs gracefully in a dive for the bottom.

Its explosive "Pffffooooffffh!" is arresting, and a reminder of our common breath: This is no giant fish from the depths, but a mammal, like us.

The grays' migration off the coast — one of the longest undertaken by any mammal — is one of the rites of spring. The grays make it look easy, knocking off the 4,300-mile, one-way journey in just 54 days, swimming at a walking pace around the clock. And some grays go even farther — swimming as much as 5,000 miles.

The northbound migration comes in two waves: Adults and juveniles usually pass by in the greatest numbers in the last week of March and early April. Mothers and calves cruise by later in April, hugging the shore to avoid deadly killer whales. They were off the coast of Monterey, Calif., last week, plowing north at about 3 mph.

Grays have good taste: They winter in the warm, crystal lagoons of Baja California, Mexico, and summer in the frigid, fecund waters of the Bering and Chukchi seas of the arctic.

Along the way, grays — even lactating mothers — don't eat much. Nor do they sleep as we know it; instead the animal rests one half of its brain, then the other, while swimming all the while, said David Rugh, a wildlife biologist with the National Marine Mammal Lab in Seattle. How they map their migration along the continental shelf is still a mystery.

Once hunted nearly to extinction, the California gray whale, Eschrichtius robustus, is a conservation success story; the gray was taken off the list of endangered species in 1994.

After reaching an estimated peak of about 26,000 animals in 1998, the population plummeted due, scientists think, to starvation associated with a warm-water trend in the grays' arctic feeding grounds. Strandings of grays jumped and calf production dropped, but the trend appears to have reversed. The population stands now at about 18,000 animals, Rugh said.

Scientists estimate about 250 so-called resident grays hang around in the summer in coastal waters of the Pacific Northwest, and even some inland reaches of Puget Sound.

Though none are true residents, some regulars return to visit year after year, earning them pet names like Batman and Buddy.

John Calambokidis, who has been studying grays in Puget Sound since 1984, has documented visits by six particular whales to the Whidbey Island region of northern Puget Sound nearly every year. They usually stay for about one to three months. Where they go after that is a mystery.

Part of what keeps the whales coming back may be the chow. The density of gray-whale food, including ghost shrimp, is believed to be richer in these waters than in the whales' summer feeding grounds in the Bering Sea.

The whales are marvelously efficient feeding machines. Even the largest grays, at 45 feet and 33 tons, thrive on a dainty diet of shrimplike amphipods, tube worms and other fare so tiny most of it wouldn't cover the dial of a wristwatch.

They will gain as much as 30 percent of their body weight in just five months, eating an estimated 900 to 2,600 pounds of food a day.

The mighty gray is primarily a mud sucker. As it vacuums the bottom, it will gouge feeding pits so large they can be seen from the air. Researchers in 1991 observed as many as 3,300 feeding pits in 11 miles of sandflats in Saratoga Passage, in Northern Puget Sound. Feeding grays can mine as much as 200,000 cubic yards of sediment a day.

The trademark signs of a feeding gray are mud plumes as they vacuum along the bottom. Their breath smells like a fecund bay at low tide.

The whales have long been at the center of the tribe's life. The tribe's flag shows Thunderbird with a gray whale in its talons, delivering it to hungry Makah, the tribal story goes, when bad weather kept whalers off the sea.

Even after a 70-year hiatus in their diet, tribal members dug right into the gray on their beach.

They stewed it, smoked it, grilled it, stir-fried it, kippered it, deep-fried it, barbecued it and boiled it, made into burgers, sausage, jerky and steak. They used the oil for dipping sauce — and for kicking up the fire in the longhouse.

Lighter and milder-tasting than seal oil, whale oil was valued by aboriginal Makah for dipping dried fish, and the smoked blubber was eaten like pork rind. The heavier bones, such as the jaw bone, were used for war clubs and bark beaters, to soften cedar bark until it was fluffy enough even for baby diapers.

The baleen was used to make rattles for whalers' ceremonial use, and the sinew for whaling gear. "We had uses for almost everything," said Maria Pascua, language specialist at the Makah museum.

The whale permeates the tribe's art and culture, including many songs. Even the word for spring in the tribe's traditional seasonal calendar means "time for whale hunting."

Something about the gray whale transcends time and culture.

"A lot of people have been profoundly affected by meeting such a large creature that shares this planet," said Will Anderson of Seattle.

A lead plaintiff in the suit to block the Makah hunt, he used to spend months on end camped at the grays' birthing lagoons along the western side of the Baja peninsula, where their gigantic but graceful form enchanted him.

"It's the immense size — it gives you a sense of humility, which is a very rare attribute for humans," Anderson said. "You can't help but take stock, and be aware of your place."

Lynda V. Mapes: 206-464-2736 or lmapes@seattletimes.com