You May Never See a Bigger Shark Than This 20-Foot Monster

If you're fascinated by sharks, have we got something you need to see.

Video of Deep Blue, believed to be the biggest shark ever filmed, has gone viral after it was posted on Facebook by Mauricio Hoyos Padilla, who runs the aquatic group Pelagios-Kakunjá.

Experts say Deep Blue is at least 50 years old and measures some 20 feet long.

While this video, taken in Mexico's Guadalupe Island, was posted this week, it's unclear when it was actually shot.

This video comes on the heels of a June post in which Padilla touches Deep Blue's fin:

Padilla is very pleased to see Deep Blue, saying, "A shark of that size is at least 50 years old and that tells me protection and conservation efforts are really working."