Have a whale of a good time at Cabrillo’s daylong fiesta.

Imagine drinking 200 glasses of milk in one gulp. That’s just a small snack for a young gray whale.

This marine fact, along with a 15-ton sand sculpture and other activities, await South Bay whale watchers Saturday at the 22nd annual Whale Fiesta, hosted by the Cabrillo Marine Museum and the American Cetacean Society.

The educational, daylong celebration is an “exhilarating, fun day to thank the gray (whales) for being around for another year and for allowing us to enjoy them,” museum naturalist Bill Samaras said.

“(The fiesta) also brings to the public’s attention (the whale’s) plight in the environmental crisis on this Earth,” Samaras added.

The Pacific gray whale is the one seen most often by Southern Californians during its migration from Baja California to the Bering Sea. Nearly extinct in 1937, today 20,000 gray whales cruise the ocean. But the gray is the only one of the 10 large whale species whose numbers are not decreasing because of commercial whale fishing, Samaras said.

Hundreds of visitors will have a chance to size up the grand gray, an animal with a heart the size of a Volkswagen Beetle, by participating in the fiesta’s main event: construction of a sand-sculpted 35-foot whale.

“All you need is a shovel and a bucket” to participate--and a willingness to get a little wet and sandy, Samaras said.

This year, organizers hope to hook enough sand volunteers to recreate a scene they spotted while tracking gray whales in Baja: a mother whale, breeching, with her calf across her back.

Fire hoses will be brought in to wet the 15 tons of sand needed to build a life-size mother whale and her 15-foot calf on the beach behind the museum.

Visitors can take a break from the sand to stroll the museum grounds, where food, exhibit booths, games and demonstrations will round out a day dedicated to celebrating such marine mammals as dolphins, porpoises and whales.

Young fiesta-goers may want to try their hands at educational, marine-themed games such as “feed the sperm whale” or a dart toss that details the migration of the gray whale. Whale videos can be viewed in the museum’s John Olguin Auditorium.

For the creative and adventurous, “The Great Cetacean Creation Sensation Contest” has returned this year. In this contest, entrants can build an orca from oak or a porpoise from plastics to compete for the best free-standing water mammal sculpture.

Demonstrations of various marine crafts such as traditional scrimshaw and watercoloring, as well as face-painting and origami, are also part of the day’s festivities.

Fiesta organizers hope visitors will discover a newfound respect for their giant water-bound neighbors, museum program director Larry Fukuhara said.

“Some kids who live in Los Angeles have never seen the ocean,” Fukuhara said. “Next time they look out at the ocean, they’ll know it’s not just water; it’s a place where many animals live.”

Limited beach parking is available for $5.50, or free parking is available in the lot at 22nd and Miner streets. A free shuttle bus will transport visitors to and from the fiesta.

What: Whale Fiesta

Where: Cabrillo Marine Museum, 3720 Stephen White Drive, San Pedro

When: Saturday, 10 a.m. to 4:30 p.m.

Admission: Free

Information: (310) 548-7562