MONTEREY, CALIF. -- The cry "Thar she blows" once signaled the harpooning of a whale, sometimes for a mere 36 barrels of oil.

Today, the whaler's call means focusing binoculars and cameras on the spouts of migrating mammals that have fought back from the brink of annihilation.

Whale watching is a multimillion-dollar industry in California, with boats up and down the coast taking landlubbers on seafaring expeditions to catch glimpses of the gentle giants as they breach and dive through the choppy Pacific swells.

An estimated 17,000 California gray whales are making their annual journey from their Bering Sea feeding grounds to the warm lagoons of Baja California for mating rituals and to give birth before returning north, a round trip of 12,000 miles.

In a tribute to the largest of the Earth's mammals, the Monterey Bay Aquarium has launched a three-month "Whalefest" of exhibits, artifacts and art focusing on the animal's size, strength, intelligence and habits.

With windows facing the open sea, the aquarium on Cannery Row is a great place for blubber lovers to hear whale songs, play whale games, watch whale movies, buy whale souvenirs and learn about the mammal's history in a setting that highlights the fish and fauna of Monterey Bay.

Steve Webster, the aquarium's education director and an avid diver and whale watcher, said the migrating grays can often be seen from the outside aquarium decks and that giant blues and singing humpbacks are frequent visitors to the bay.

"The gray whales are best for watching because they do migrate close to shore," said Webster. "Monterey Bay is a great place with some 26 species of marine mammals, of which a dozen or so are whales. So, for variety, this is a particularly good spot."

An undersea canyon rich in nutrients and a variety of fish and krill attracts whales and other mammals to the rim of the bay, said Webster.

The gray whale, considered an endangered and depleted species before being protected along the coast starting in 1946, has made a comeback unmatched by any other species of whale. Webster said its population may even be up to aboriginal levels.

"But for all the other species, we're far from that. All of the others have been hunted down so far that some of them may never recover to their former numbers.

"Something like 1,700 humpback whales were killed in Monterey Bay in the space of three years in the early 1900s. They used to be one of the most common whales singing here. They haven't begun to come back to those figures."

The blue whale, which, at up to 100 feet, is the largest of the cetaceans, has been again visiting the bay during the past couple summers, said Webster, with 15 to 20 of them feeding off the submarine canyon.

"They're magnificent," said Webster. "Gray whales are exciting, but when you hear a blue whale spout a mile or two away, it sounds like the Santa Fe {train} going by. They're just incredible."

While the whales swim past outside, a series of five major exhibits inside the aquarium runs through April 30 and acquaints visitors with the mammals, including presenting such facts as:

Whales have an exceptionally keen sense of hearing.

They have small hipbones and a hidden set of fingers in their fins, remnants of their land-dwelling ancestors of 50 million years ago.

They can't survive on land; their body weight would collapse their lungs.

Blue whales can weigh 150 tons, as much as 30 elephants, 150 cows or 2,000 people.

Sperm whales stay deep, chasing squid and fish down to 3,500 feet.

Orcas, or "killer whales," live in family "pods," each with its own calls or dialect.

Humpbacks have the greatest vocal range of all whales, making low moans, whoops and birdlike chirps and whistles.

Between 1910 and 1984, whalers officially killed 715,566 sperm, 357,132 blues and 165,537 humpbacks worldwide.

One exhibit shows how whales have been treated in film, including "Moby Dick" and "Nanu, the Killer Whale" and the search for vanished humpbacks in "Star Trek IV." A wall of 8,000 "Big Macs" shows how a blue whale's 3 million calorie daily diet translates in hamburger terms.

A lot of displays are aimed at children, including a life-size board game in which the participants become gray whales trying to migrate along the Pacific Coast, battling obstacles. There are also puzzles, quizzes, a reading nook, zoetropes, storytelling and special activities for youngsters.