San Antonio — If you thought the wildest thing you’d see on the River Walk was a floating margarita, think again.

Over the past few days, curious onlookers along the downtown stretch of the San Antonio River have reported something straight out of a movie scene — shark fins slicing through the water. Yes, fins. In the River Walk. 🦈

The buzz started downtown, where visitors and locals alike stopped mid-stroll, phones out, trying to catch a glimpse of the unexpected spectacle. Then, just when the city thought it couldn’t get any stranger, the fins were spotted again — this time making their way toward River North near the historic Pearl on Saturday, March 28.

Before anyone starts canceling their river cruises, there’s a twist to the tale.

The sightings are part of a creative promotional campaign for Netflix’s upcoming thriller THRASH, set to debut on April 10, 2026.

The film stars Phoebe Dynevor, Whitney Peak, and Djimon Hounsou, and follows a harrowing story: when a catastrophic hurricane slams a coastal town, residents find themselves trapped in rapidly rising floodwaters — waters that aren’t empty. They’re swarming with relentless sharks.

In a city known for its creativity during major events and activations, this stunt blends perfectly into San Antonio’s love for spectacle. The illusion of sharks gliding through the river has transformed an ordinary weekend into a citywide conversation, with social media lighting up as people try to confirm what they’re seeing.

It’s part thriller, part urban legend, and all marketing magic.

Whether you’re snapping photos along the River Walk or catching the “fins” near the Pearl, one thing is certain — San Antonio just got a preview of the suspense that THRASH promises to deliver.

And come April 10, those fins won’t just be in the river — they’ll be on screens everywhere. 🍿🦈