Bay Area Beaches Are Chock-Full of Mysterious Blue Creatures Again. Here’s How to See Them

They’re an otherworldly sight: blue and iridescent. They have no clear eyes, mouths or body parts analogous to our own.

And rising from one side — is it their back; hard to tell — is a transparent sail, which these little seafarers use to catch the wind.

Sightings of Velella velella, also known as “by-the-wind sailors,” have proliferated along the Bay Area coastline this week, captivating beachgoers and drawing the attention of the climate- and ocean-curious.

These compelling creatures visited our shores last year, too. But this year they seem especially abundant — to the extent that “beaches in this area appear blue from a distance because of the numbers of Velella right now,” according to Jackie Sones, research coordinator at the UC Davis Bodega Marine Reserve in Bodega Bay.

What are these things?

Velella velella are best described as colonies of cells, living and working together. They’re classified as hydrozoans, related to jellyfish and sea anemones.

Every specimen has a gas-filled “float” or raft, with a mantle surrounding it, tentacles dangling below to catch prey and a mouth at the center of its underside.

They also have reproductive structures that bud off tiny, jellyfish-like offspring and a sail that rises from the top of the raft to catch the prevailing wind.

These sailors eat plankton and are eaten by larger animals, including ocean sunfish (aka Mola mola) — itself one of evolution’s strangest and most delightful concoctions.

Where can I see Velella velella in the Bay Area?

They’ve been reported in San Francisco — at Baker Beach, Crissy Field and Ocean Beach — as well as along Santa Cruz, Pescadero and in Bodega Bay.

Head to your local stretch of coast, and there’s a chance you’ll spot them.

For how much longer will I be able to see them?

How long they’ll stick around depends on the wind. Velella velella often appear in spring or early summer in Northern California, when upwelling and winds align to help them proliferate and be pushed ashore. The good news, though: Sightings tend to last days to weeks.

That’s because of springtime “upwelling” in the ocean: When deep and cold water rises toward the surface. “Upwelling brings lots of nutrients, and lots of nutrients bring phytoplankton and zooplankton,” Raphael Kudela, professor of ocean science at UC Santa Cruz, told KQED in 2025.

This year, they could persist longer. Velella numbers are linked to warm water, and the Pacific Ocean is experiencing a marine heat wave, with the possibility of a strong El Niño system developing. If that happens — and if prevailing winds keep pushing them onshore — we could continue to see by-the-wind sailors through the summer.

Can I touch Velella velella?

Yes, cautiously. Handling Velella velella doesn’t pose much risk, especially if they’re dead and dried out.

Be warned, though: Living Velella do have stinging tentacles, like their Portuguese man o’ war cousins. A child or dog putting one in their mouth could get hurt.

Are they here because of global warming?

Maybe — but not necessarily.

While their appearance is fairly typical this time of year, climate change is nonetheless expected to increase the frequency and intensity of marine heat waves, likely leading to more abundant and frequent sightings of Velella velella.

KQED’s Sarah Mohamad contributed reporting to this story.