In Brewer's photo, which has since become a viral sensation, the steel-grey beast emerges from emerald-coloured waters, lured by a pair of fish heads tied to a rope as bait.
"I wasn't even a little bit frightened," Brewer boasted to Time Lightbox about the fateful moment.
"When you're there and you're in their presence, it's not scary. They're beautiful and graceful, and you can see how intelligent they are."
The art teacher said she took about 30 shots with the camera in burst mode, but none was as dramatic as that one toothy picturet.
"I knew immediately that that photo was going to do something," Brewer told Time Lightbox.
Upon her return home, Brewer hung her now-famous picture of the shark with its mouth agape in her classroom at Whitman Elementary School in Washington Township to inspire her young students.
The vivid snapshot has been shared thousands of times on social media sites and has been the subject of fawning news articles, blog posts and TV segments.
But Brewer also has been subjected to criticism from shark advocates over the use of bait in the taking of the photo.
Speaking to GrindTV, the New Jersey educator explained that the fish heads used to lure the shark were pulled around and out of the way of the cage to make sure the sea creature didn't lunge and the steel bars.
"That's one thing that we learned right off the bat, is that you never want the shark to make contact with the cage," she noted.
"And you also don't want the shark to eat the bait. You don't feed the sharks; that's not what we want to do."
Brewer added that the fish-eye lens on her camera made the shark appear closer to her than it was in reality, which was about 3 feet from the cage.
She said the shark came out of nowhere, and she was simply at the right place and at the right time with her trusty GoPro at the ready.
"I'd been waiting for this kind of experience my whole life," Brewer told LightBox.
The makers of GoPro took notice of Brewer's ringing endorsement of their camera and featured her photo on their Twitter account, which helped the shark-tastic snapshot go viral.
- Daily Mail