Aliens? Submarines? Gassy whales? Mystery bubbles off California coast spark intrigue, theories

Salvador Hernandez, Los Angeles Times on Nov 19, 2025

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LOS ANGELES — Is it a gassy whale? A top secret submarine? Godzilla rising from the surfer-filled waters of Hermosa Beach?

Residents have been stumped over a patch of bubbles rising out of the ocean off the coast of Hermosa Beach this week, prompting several beachgoers to speculate at what exactly is under the surface and causing the water to spume.

Videos of the bubbles, visible between 33rd Street and Longfellow Avenue, spread on social media, with commenters offering a variety of wild and not-so-wild theories. Neighbors stood on the street in the rain, gazing out into the ocean, wondering what was causing it.

The answer to the bubbles mystery turned out to be far from interesting or surprising.

A major clue to uncovering the mystery came Tuesday, when a boat was spotted out on the water, floating near the bubbles that were drawing curious questions.

"Same spot as yesterday," said Mark Zurales in a video posted on Facebook, showing a boat on the water and a circle of white bubbles surfacing beside it.

The video generated plenty of theories but few answers.

"New submarine testing??" one resident wondered.

"My guess would be a gas release," another pondered.

Others wondered if it might be a bait ball, where small fish gather together in a small spherical shape in the water, but another resident noted there were no sea gulls flying out overhead, looking for a quick lunch.

One resident noted that Northrop Grumman had recently unveiled an unmanned submarine. Perhaps the manta ray-looking underwater vessel was being tested in their backyard?

Another one responded to the video with their own theory: a set of alien emojis. One jokingly asked, a gassy whale?

"I was on the case, I had to go down there and see it," said Zurales, who on Tuesday decided to take a surfboard and paddle out to the bubbles and get some answers.

On the way out, he ran into two lifeguards on the sand who said they too had no idea what was out there, but said the bubbles seemed to be as strong as if they had been created by a Jacuzzi.

In a video posted on Facebook, Zurales is seen paddling out into the water until he reaches a boat near the bubbles, and asks those onboard what is going on. The boat occupants were contractors working on an underwater fiber optic cable. Mystery solved.

Rick Devinney, with Drake Traffic Control Services, a contractor working on the site, told The Times that the transpacific fiber optic cable runs under the Pacific Ocean from California to Asia.

"They're blowing air out to make sure that the conduit is clear," Devinney said. "They're making sure that everything is clear to add more cable."

A crew on the street has been working this week on blowing air through the line, generating the bubbles that have been showing up in the water along the cable, he said.

The work, he said, should be done by Friday.

The answer, Zurales said, was not as fun as some of the online speculation.

"It was just funny seeing everybody was on the same boat, speculating," he said. "Somebody had to get to the bottom of it."