A college student on a fishing trip in the Gulf of Mexico caught dramatic footage of a big tiger shark repeatedly attacking a hammerhead on a fishing line.

Shot on July 17, the video shows a hammerhead shark struggling on the line. Then, a tiger shark cruises in and bites the hammerhead.

The attack went on for several minutes, until the tiger shark "grabbed the hammerhead around its head, broke the line, and then dragged him straight down," says Ryan Willsea, who made the video with his brother Aaron, and whose line caught the hammerhead.

"It was an incredible thing to see and catch on film," he says.

Willsea spent three days fishing in the Gulf during a vacation to the area,