Narrator: OFF THE COAST OF GUADALUPE ISLAND,

A TEAM OF RESEARCHERS ARE SEARCHING

FOR THE LARGEST GREAT WHITE EVER RECORDED --

"DEEP BLUE."

THAT HAS LED THEM OVER AN EXPANSE KNOWN AS "THE LEDGE."

♪♪

Man: Ohh!

♪♪

[ INDISTINCT SHOUTING ]

♪♪

Whoo-hoo!

♪♪

Man: AH, WHAT A DIVE.

WHEN THAT THING HIT, IT WAS JUST, LIKE, BOOM.

SHARK DOWN THERE MUST HAVE MEASURED

AT LEAST 16, MAYBE 17 FEET.

Narrator: WITH THE CAGE AT THE SURFACE,

THE TEAM ARE EASY TARGETS FOR THE HUGE SHARKS LURKING BELOW.

McMillan: THEY KEEP COMING FROM THE DEEP.

I'D SAY THEY'RE ABOUT PROBABLY 200 FEET DOWN.

Narrator: BUT THE CAGE ISN'T THEIR ONLY TARGET.

THE TEAM WITNESSES ONE GREAT WHITE BITING ANOTHER

IN WHAT APPEARS TO BE A PREDATORY ATTACK.

SCIENTISTS USED TO BELIEVE THAT THIS BEHAVIOR WAS RARE.

BUT A RECENT DISCOVERY HAS LED TO A CUTTING-EDGE THEORY --

GREAT WHITE SHARKS COULD FEED OFF EACH OTHER.

THERE ARE SOME THEORIES THAT WHITE SHARKS ARE CANNIBALISTIC.

THIS HAS TO DO WITH A SHARK THAT WAS TAGGED IN AUSTRALIA.

THIS SHARK HAD BEEN EATEN BY A LARGER SHARK.

Narrator: THE DISAPPEARANCE OF THE NINE-FOOT GREAT WHITE

NAMED "SHARK ALPHA"

HAS FASCINATED RESEARCHERS SINCE 2003.

MONTHS AFTER SCIENTISTS PLACED A TAG ON HER,

THE DEVICE SUDDENLY WASHED UP ON SHORE...

AND THE DATA RECOVERED FROM IT

LED SCIENTISTS TO A STARTLING CONCLUSION.