White humpback whales look like massive ghosts floating through the ocean, and like ghosts, are rarely seen. That's what makes the recent sighting of "Migaloo," an albino humpback was first seen in 1991, so special.

Migaloo was spotted by whale watchers this week off Australia's Green Cape in New South Wales. Onlookers recorded Migaloo effortlessly gliding through the ocean, cresting the surface.

Oskar Peterson, with the White Whale Research Center, confirmed the sighting.

"He sort of glows in the water like a fluorescent blue," Peterson told ABC News Australia. "He's quite an amazing sight."

News of Migaloo always travels fast. And soon, swarms of interested parties were out hoping to catch a glimpse.

"The helicopter crews are all out photographing him today," said Oskar Peterson. "He's giving us all quite a parade this year."

Part of the reason spotting a white humpback is such a rare occurrence is because there are only two in the world. For more than two decades, scientists assumed Migaloo was one of a kind, but in 2011, whale watchers saw another all-white humpback. Experts tracking Migaloo's movements since 1991 were able to confirm that, indeed, it was not Migaloo himself.

Thus, the second white whale was dubbed Migaloo Junior.