“We’re here,” Ranjith said, cutting the engine. “Drop anchor now!” Deepa, the intern, threw the anchor off the bow and stepped aside as the chain and heavy rope unspooled into the water.

On the transom, the sonar man, Suresh, squatted over the ROV, a small robot about the size of an office copy machine. Tethered to the boat by a long, thick umbilical for power and controls, it could drop into the depths, illuminate the darkness with a quiver of powerful lights, and capture what it saw with a high-definition camera. Despite his rather nautical job at MOCHA, Suresh was not much for boats and had never learned to swim. But he was an expert in underwater electronics like the ROV, having interned at Woods Hole in America, and working on the R/V Petrel when it had discovered several important World War II wrecks in the Pacific a few years earlier.

“She’s ready to splash,” Suresh said, giving one last tug on the cable connection as if to prove his point. He and Upali lifted the robot by its bottom skids and shuffled to the edge of the transom. “Bon voyage, little friend,” Suresh said as it splashed into the water and disappeared below the surface.

Upali and Suresh settled in at the computer monitor inside the forward cabin. The screen showed a direct feed from the camera on the front of the ROV as it descended through 300 feet of ocean: darkness, with the occasional cloud of drifting particulate reflected in the craft’s 10,000-lumen flood lights. Deepa hovered over their shoulders. This was her first field work as a MOCHA intern, and she was excited at the prospect of actually finding something. Ranjith sat on the transom, smoking.

“We should have hit bottom by now, eh?” Upali said. The ROV’s depth gauge showed 357 feet.

“Well, according to the charts, we’re literally on the edge of the dropoff, so if we overshot by even a few feet, we’d be over the side in very deep water,” Suresh said. “Let me alter the heading a bit and bring her back up a ways.” He pulled on the joystick delicately with his fingertips. The depth reading changed, despite the continuous blackness on screen. 342, 337…

“Whoa, what’s that?” Deepa’s finger darted out, poking the monitor. They all leaned in. The video feed clearly showed a twisted procession of railing stanchions atop a coral encrusted slab of steel. The ROV had come up almost beneath it. Suresh cursed and quickly maneuvered to avoid entangling the umbilical cable. Must be the bow, Upali thought.