Transcript for Shark Stalks Kayakers Off Coast of Florida
Let's move on. Matt Gutman has been with us all week. And you'll remember, we showed you this video of Matt demonstrating what to do if you encounter a dangerous shark. Well, it really happened to these kayakers who were followed by a shark for miles off the coast much Florida. And our Matt Gutman, of course, has the story. Reporter: If the fin slicing through the waves just feet from this kayaker wasn't jawsy enough, take a look at what the camera reveals when dunked into the water. The unmistakable shape of a hammerhead shark, tailing them for two hours. He hit my rudder and jogged the whole kayak. Just following us steadily and creepily. A little bit of "Jaws" action. They were off of palm beach. The shark, estimated as big as their kayak, 13 feet. It was a big shark. Just a little -- Hairy, I would think. Reporter: Hammerheads are not considered as grandfather as great whites with fewer than 30 attacks in recorded history. But they can be territorial as this duo learned. Instead of staying out of the water, they jumped in. That was not the smartest idea we have had. Reporter: Circled by another hammerhead, they jab at it with their spears before finally wising up and getting back in the boat. Close encounters from coast to coast. And experts say they're only becoming more common. Possibly because the warm waters of el Nino are attracting fish. And the bigger fish eat them. For "Good morning America," Matt Gutman, ABC news, Miami. Can't get enough.
This transcript has been automatically generated and may not be 100% accurate.