At around 10:45 p.m. on a Friday in March, the order came to turn out the lights about 3 kilometers, or a mile and a half, from shore. Chhuan, the speedboat’s driver, who gave only his first name, killed the engine, and in the pitch black, rolling on the waves, the fishing village of Chroy Svay was barely visible. The crew huddled around a digital map, checking that they wouldn’t run into fishing nets laid by their fellow fishers that morning.

“What did you say? It’s a trawler, right?” Sedh Phoeun, another local fisher on board, was frantically asking his brother over the phone whether the steady hum of the trawlers’ engines was still audible back on shore. From the speedboat, Phoeun had temporarily lost both sight and sound of them.

“I see,” Phoeun said into the phone before relaying directions to Chhuan: Two trawlers were heading west. Perhaps they’d heard the sound of the speedboat and were trying to flee these fishing grounds.

Phoeun, Chhuan and the other men on board the speedboat aren’t police or navy. They’re members of the Chroy Svay community fishery (CFi), a group of local small-scale fishers, and they’re responsible for patrolling the nearly 13,500-hectare (33,300-acre) body of water from which they pluck their livelihoods.

But while these waters are meant to be managed sustainably by the CFi to ensure its members can fish to feed their families, commercial trawlers have been illegally entering the CFi’s fishing grounds, scraping the sea clean of life and, with it, the community’s ability to survive.

Skimming atop the waves, following the now-audible thrumming of the trawlers, Chhuan pointed as the lights aboard one trawler’s deck flicked on. A flurry of activity was visible as the speedboat drew nearer, having traveled some 6 km (3.7 miles) but now only 1.3 km (0.8 miles) from shore in Cambodia’s southwestern province of Koh Kong.

One trawler had already pulled up its net and the crew were bundling their catch into the hold. The other trawler, still with its lights off, wheeled around to face Chhuan’s speedboat as it approached.

Suddenly, headtorches aboard the trawlers sent powerful beams of light out of the gloom, illuminating the faces of the men on board the speedboat. Ordinarily, a speedboat would mean either the Royal Cambodian Navy or the Fisheries Administration, hence the trawlers’ earlier apparent decision to run. But the CFi has no authority to arrest the trawlers or seize their illicit catch, and now they were taking a more aggressive stance.

According to bathymetry data published by the General Bathymetric Chart of the Oceans (GEBCO), the trawlers were operating in waters less than 10 meters (33 feet) deep, in violation of Cambodian law, which prohibits trawling in the near-shore exclusion zone that comprises depths of 20 m (66 ft) or less and is reserved for small-scale fishers like CFi members.

The two boats, Phoeun said, could have been operating as pair trawlers, which is also illegal in Cambodian waters: Two vessels hoist a dragnet, sometimes kilometers long, between them and scoop up everything in its path. But in the pitch-black chaos it was difficult to see what was happening on the water — or below it.

The unlit trawler made several moves to ram the speedboat, forcing Chhuan to perform countermaneuvers, wary that there may still be an unseen dragnet that could catch his propeller and leave the speedboat stranded.

After almost an hour, with no means of communicating between the trawlers and the speedboats, the trawlers’ crews appeared to hedge their bets and left. It was a victory, albeit a small one, in a fight for survival that small-scale fishers have almost lost to illegal trawling.