A strikingly massive great white shark, one of the largest ever documented, was spotted by divers in Hawaii on Sunday as the apex predator feasted on a sperm whale carcass.

The sighting of “Deep Blue” off Oahu was remarkable because the handful of previous sightings were documented 2,600 miles away at Guadalupe Island off Mexico’s Baja California peninsula.

“My first reaction was just disbelief,” Mark Mohler, who captured the images for this story, told For The Win Outdoors. “She followed three tiger sharks in toward the whale carcass, and her sheer size made them look like barracudas.”

Photographer George T. Probst announced the Deep Blue sighting via Twitter on Tuesday, when another enormous white shark was spotted near the whale carcass.

Deep Blue has unique skin markings. Probst said he compared footage captured Sunday to photos in the Guadalupe Island database, and that the ID was confirmed by Michael Domeier and Nicole Nasby Lucas of the Marine Conservation Science Institute. MCSI has tagged dozens of Guadalupe Island white sharks.

Those sharks typically migrate into open ocean, as far as Hawaii, during late fall or early winter. Most return to Guadalupe by early or mid-summer.

White shark sightings off Hawaii, however, are rare.

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Deep Blue, believed to measure at least 21 feet, became famous after being featured by Discovery in 2014 (with footage captured in 2013).

The gargantuan shark generated headlines again in 2015 when Mauricio Hoyas Padilla, a Mexico-based scientist, shared footage showing the shark dwarfing divers in cages at Guadalupe Island.

On Sunday, Deep Blue was fattening up on sperm whale flesh as the carcass drifted slowly south, away from Oahu.

Diving with Mohler were Andrew Gray, Kimberly Jeffries, Laura Rock, and Daren Babula. They received surface support in boats from Danny Roberts, Tim Andrews, and Heather Armstrong.

“After I spent some time with her, and then again when we confirmed her identity as Deep Blue, it was an incredible feeling of euphoria,” Mohler said. “Everyone was in awe when we saw her. It was both disbelief and euphoria. Her size was absolutely incredible.”

–Images showing divers with Deep Blue are used with the permission of ©Mark Mohler

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