As the riot that marred the U.S. Open of Surfing in 2013 recedes in the rear mirror, Huntington Beach police say they are remaining vigilant not only to prevent a recurrence of the unrest but also to prevent any of the terrorist violence that has afflicted popular sports events in recent years.

From Sunday, July 29 through the event’s close on Sunday, Aug. 6, police will be out in force, on the alert for problems big and small, as hundreds of thousands flock to the beach for the signature surfing event, said police Chief Robert Handy.

Police are “dialed into federal intelligence sources” to stay abreast of any potential terrorist threats, Handy said.

“We evaluate the threat picture,” he said. “There are no specific threats here or anywhere in California right now, but we look and plan for multiple scenarios.”

A new wrinkle police are also considering this year is the possibility of political or social protests, which Handy said have recently become more prevalent.

Police say measures implemented in recent years have significantly changed the vibe at the U.S. Open of Surfing — from alcohol-fueled brofest to family-friendly sports competitions.

Independent security personnel will screen for metal and alcohol in beach-goers’ coolers and backpacks. They’ll use a hand-held “preliminary alcohol screening device” called a sniffer, which tests for alcohol in drinks. Cameras have also been added that will be monitored by police throughout the venue and surrounding areas. Giveaways by vendors have been scaled back — no more tossing promotional items into the crowd. There is no more live music, and bars and restaurants on Main Street, which used to spread out onto the sidewalks to capture business, are seeing that practice pulled back. Police officers will patrol on foot, ATVs, bikes and other vehicles, Handy said. And, since 2014, mounted police from departments from Huntington Beach and other local cities will also patrol.

It’s “not quite all hands on deck,” Handy said, but it’s significant and geared to the size of crowds.

All of this is meant to prevent a reprise of past unruliness, or worse, police say. In 2013, a fracas broke out and quickly escalated about two hours after the event had ended. Several portable toilets were overturned, stores were vandalized and it took police using pepper spray to restore order.

Eventually, 20 people were arrested, most after-the-fact from video and photo evidence.

The focus is “to continue to build this into a family-friendly actions sports event that any family can come out and enjoy and feel safe,” Handy said.