The river's dark waters are stunningly framed by shades of green and cascading vines in this remote corner of the Republic of Congo.
As Eckel's eco-guard unit turns a corner, he gives the order to cut the engines. We're approaching the first suspected site. The boats coast silently against the hum of the forest.
The team quietly assaults, but the camp is deserted.
A member of the team checks the ashes. "It's still warm, they must have left early morning, we missed them by a couple hours," he says.
For the next grueling, hot eight hours, the same scenario repeats itself.
Then, suddenly around a bend, the unit spots rising smoke. They rush ashore, fan out and within seconds the first gunshot rings out. The men sprint through the dense and disorienting terrain, forcing their way though the undergrowth and knee-deep water as even more bursts of gunfire echo through the forest.
Pumped on adrenaline, eco-guard Brice Moupele animatedly re-enacts what happened when he saw the poachers.
"I yelled 'Stop, stop!' and shot in the air," he says.
"The man tried to shoot at me. I tackled him and grabbed his gun, but he was able to escape." Moupele happily displays the captured weapon.