Whale watchers in NSW got more than they’d bargained for on Saturday morning when a pod of orcas attacked and devoured a humpback whale.

The ordeal took place only 2km off the coast of Ballina on a once-in-a-lifetime morning whale watching tour.

Dean Fuchs, the skipper of the boat said it was one of the rarest experiences he’d ever had on the water.

“It was a once in a lifetime experience. It’s been one of the things I have wanted to see my whole life and to finally get to see that was pretty special,” he told ABC.

According to witnesses, the calf was separated from the mother and a male humpback before the orcas attacked it. While this is a natural occurrence in the wild, it’s rare for humans to watch it unfold.

Dean said that about 30 orcas took part in the attack on what was otherwise a calm tour.

Following the attack, the orcas continued to hang around the boat for another two hours, likely celebrating their kill.

“We were watching the mother whale, her baby and a male having a great time splashing their tails and pectoral fins for quite a while, when out of the blue a pod of orcas turned up and started circling around the whales and jumping over and onto the baby humpback,” a witness, Julie Cummings said.

“There was a lot of commotion and they eventually separated the baby from the mother and the male,” she told ABC. “They proceeded to basically smother the baby by jumping onto it and covering its breathe hole [blow hole] and holding it down. It was all so sad but at the same time amazing.”

According to witnesses, the whole boat was in awe of the rare sighting, with “the occasional OMG” breaking up the otherwise silent crew.

The adult humpbacks tried to save the baby, but it ultimately succumbed to its injuries and was last seen on its back with blood around its mouth.

“We had an amazing experience, something the grandkids, my daughters, sister and myself will talk about for years to come, and to think we weren’t so keen on going that morning as it was a cold and miserable day” Julie said.

Image: Out Of The Blue Adventures