Guests aboard a whale-watching vessel caught a rare sight Tuesday when a pod of orcas attacked a gray whale and its calf off the Southern California coast.

A Harbor Breeze cruise out of Long Beach witnessed a mother gray whale fighting off a female Eastern Tropical Pacific orca near the Palos Verdes Peninsula in Los Angeles County, Assistant Port Captain & Spokesman Tyler Askari told KTLA.

Video shared by Askari on social media shows blood in the water during the battle, which unfolded right next to the boat and its passengers and had started several minutes before they arrived.

“The adult gray whale did end up surviving after the orcas gave up on the fight,” Askari said. “The juvenile gray whale did appear to lose … and never resurfaced.”

The pod of about 10 killer whales was first spotted last month by tours out of Long Beach and Newport Beach, and guides have documented countless instances of the orcas hunting common dolphins. The attack on the gray whale, however, was even more extraordinary.

“A believed absolute first for the SoCal region,” Askari said.

Experts assumed the pod would quickly return to the warmer waters of Mexico where they are typically found. Instead, they have been enjoying the SoCal coast for several weeks and feasting on the abundant prey off the coast of Los Angeles, Orange and San Diego counties.

“They’re going to make their way back down to Mexico at some point. But we’ve been so lucky …. to be graced with so many sightings of these killer whales,” Jessica Rodriguez with Newport Landing & Davey’s Locker told KTLA last week.