“As I started reeling in, the rod bent until the tip was almost in the water,” Gerson said, “Soon I wasn’t reeling, but instead holding on for dear life as line was running out of the spool at an alarming speed.”

A fishing guide onboard estimated the giant fish to be more than 300 pounds and possibly 50 years old.

That prompted the group to label their catch “The Dinosaur.”

Gerson wanted to document the encounter with the shark-like creature, so he jumped in the water and took a few photos.