The Underwater Film Festival floods the Peninsula with stellar ocean stewards.

The annual Monterey Underwater Film Festival has been a well-constructed and appealing event all along, bringing world-renowned underwater filmmakers and photographers to the stage to show highlight reels of the best footage of their careers, as well as sneak previews of upcoming stuff.

These are men and women obsessed with capturing and sharing the most exciting, profound and beautiful images from the planet’s watery realms, all convening this Saturday evening at the sumptuous Golden State Theatre.

If it was already a must-see, this year festival founder Berkely White, owner of Cannery Row’s Backscatter Underwater Video & Photo, has outdone himself. This year he’s bringing Sylvia Earle.

That’s National Geographic explorer-in-residence Sylvia Earle. That’s the first woman chief scientist of the U.S. National Oceanic and Atmospheric Administration Sylvia Earle. That’s Time Magazine’s first Hero for the Planet awardee Sylvia Earle. The deep-sea diving legend, submersible designer and role model is revered as one of the first and most compelling protectors of the ocean. She even has her own Lego figure (outfitted with scuba gear). And she’s been here before.

“Most people, and I was one, thought the [Monterey Bay] was characterized by sea otters, abalones, harbor seals, whales, krill, squid, birds,” she says. “All of that is true. But the part I’ve come to know and love is that great canyon that starts at Elkhorn Slough and goes down, down deeper, longer, wider than the Grand Canyon.”

She’ll talk and show a trailer for the film Mission Blue at Saturday’s film festival. Created by the makers of The Cove, it’s part biography, part adventure story, part ocean conservation plea, a summation of her life and work, a big push for more urgency about the ocean’s fragility.

“We all call her the Mistress of the Deep,” White says. “She’s an incredible pioneer of early research subs that went to bottom of the ocean. She was doing this back when there were no women in that field whatsoever. She was a hero to hundreds of women who weren’t even considering a science career.” (Read more of the interview with Sylvia Earle on theWeekly’s arts and culture blog.)

There are three others also showing their work on the big screen and talking about it on the wide stage. They’ll take the audience to the Arctic Circle, the Brazilian jungle and the ocean off Baja.

Earle is a legend. But Adam Ravetch is also a big name in the underwater filmmaking game. He’s a marine naturalist, scuba diver and Arctic specialist, who for 20 years has been taking his equipment and crew to one of the most punishing climates on the planet. He’s come back with crystalline footage for projects like the feature film Arctic Tale, a 10-year project about global warming produced by National Geographic and narrated by Queen Latifah.

“He’ll share what insanity it is to try to dive in the Arctic,” White says.

Brazilian filmmaker Cristian Dimitrius forays into the jungles and waterways of the Amazon’s vast rain forests to capture creatures like anacondas, freshwater dolphins, alligators and insects for TV and films that have made him a celebrity in Brazil. A youngish and photogenic figure, he puts himself into scenes, holding or interacting with the animals he encounters for shows like The Secret Life of Predators and River Monsters. In one scene, he lets blood-sucking eels attach themselves to his face mask and his neck.

“His imagery is fantastic,” White says. “It’s not just the normal junk that passes for science documentary stuff. It’s really creative filmmaking.”

Erick Higuera, from Mexico, will show footage of an awesome assortment of sea animals that inhabit the waters off the Baja Peninsula, including great whites, humpback whales, whale sharks, manta rays and dolphins. It’s a great oceanic society that makes for truly inspiring sights, shot with daring proximity to their point of view.

“Really big action,” White says. “In a year or two you’ll most likely start seeing Erick working for Nat Geo and BBC.”

Saturday’s films and appearances by these seafaring celebrities are just the most visible part of the three-day Monterey Shootout. The part that the land-bound aren’t privy to is the contest that draws multitudes of ocean-diving photographers and filmmakers. They’re tasked with diving into the Monterey Bay on Friday to capture the best footage they can in 32 hours, and to present that footage on Saturday for judging and prizes on Sunday. The winning work will be shown at Monterey Peninsula College’s Lecture Forum starting 3pm on Sunday.

Saturday evening’s films and talks at Golden State Theater is where those divers will surface to meet and mingle on land, a climax that comes not at the end but in the middle, one that forges into the next frontier in ocean exploration, which Earle says is closer than we think.

“Maybe the most important [frontier] is the mindset,” she says. “Only 5 percent [of the ocean] has been seen. The greatest insight is the magnitude of our ignorance. That’s the frontier.”

THE MONTEREY UNDERWATER FILM FESTIVAL takes place 7pm (doors at 6pm) Saturday at Golden State Theater, 417 Alvarado St., Monterey. $10-$15/adult; $6-$10/child 12 and under. 645-1082, www.Backscatter.com, www.GoldenStateTheatre.com.