TMZ has obtained shocking footage capturing the seconds after the 10-year-old boy -- who was the victim in this case -- frantically swam to the top of the tank as his father, who heroically jumped into the water, helped him over to a ladder. It's as dramatic as can be.

Eyewitnesses tell TMZ ... the dad carried the boy up the ladder onto a landing before rushing off with his son to get him medical attention, which can be seen in one of the photos. We're told the boy's mom and Atlantis Resort staff assisted the father in his efforts.

According to one source ... the boy climbed down into the tank with a chaperone on January 15 as part of the shark experience for guests at the Atlantis Bahamas Resort.

Wearing a large white helmet and heavy oxygen tank, the boy stood with the chaperone on the floor of the tank as the sharks whipped past them. Two of the reef sharks were aggressively swimming around the boy -- and one of them darted through his legs.

This caused the boy to lose his footing and straddle the shark, which turned its head around and sank its sharp teeth into one of his legs near the calf area. That caused him to bleed.

The boy's mom freaked out, screaming, "Did that just bite him?" She then realized, "Oh my gosh, that's my son." The mom, along with the boy's father, sprung into action to assist.

The Royal Bahamas Police Force said the boy -- on vacation from Maryland -- got bit on the right leg and was taken to the hospital ... thankfully, he was in stable condition, and Atlantis shut down their tanks immediately.

Remember, we got a hold of footage and photos that showed what this same shark tank looked like just a couple days prior to this incident -- and while it might've looked a bit crowded in there (with more sharks than humans), we were assured that's standard.

This attraction at the resort has since been shut down ... as they reevaluate their procedures for their guests moving forward.