Depth Charge by Jason Heaton (carter reed .txt) 📗

has a romantic sound to it, largely thanks to tales of Caribbean treasure hunts and Clive Cussler novels, but in reality, it is stupefyingly boring. The first step is to identify anomalies on the ocean floor, those features that don’t appear to be naturally occurring objects such as rocks, coral heads, or schools of fish. This is done by dragging a side-scan sonar device behind the boat in a systematic pattern, a process known as “mowing the lawn” and is just about as exciting as walking up and down a suburban backyard. The sonar device, known as a tow fish, is shaped like a torpedo, with a cylindrical body and stabilizing fins at its back end. As it moves through the water, the tow fish sends audio pulses into the depths, which bounce back off the sea bed. This paints a sort of electronic picture of the terrain on a laptop screen on the boat. Man-made objects, usually shipwrecks or pieces of debris, are recognizable by their more geometric shapes on the screen. Right angles and straight lines rarely occur in nature. These anomalies are marked with GPS coordinates to be investigated more thoroughly later with the ROV. A day spent mowing the lawn under the tropical sun, watching a computer monitor for anomalies, is only tolerable with the promise of actually finding something, which rarely happens.

A few weeks earlier, a fisherman had snagged his line on what he assumed was a rock ledge and pulled up a faded orange life ring with some indistinguishable writing on it. A shipwreck? That would explain the good fishing. Fish tend to congregate around wrecks for their relative shelter on barren sea floors, but there were no known wrecks in this area. Word got back through the fish market gossip, on up to a local politician, who alerted the naval base in Trincomalee. The navy didn’t have the time to go on wreck hunts, so it passed the message on to MOCHA’s offices in Colombo, and that’s how Upali Karuna found himself slowly motoring up the coast on the Taprobane on this cool morning.

After an hour and a half of mowing the lawn, the MOCHA team decided to investigate a promising anomaly from the sonar scans, a long shadow on the slope of a deep ocean trench that slashes in from the continental shelf towards Batticaloa. Here the sea deepens from 150 feet to over 300 quickly, and then drops over a precipice into 2,000 feet of dark water.

“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.

“Follow that railing,” Upali said. “To the right must be aft.” Suresh didn’t answer, but the view on the monitor, with its wide-angle lens, zoomed along the upper hull of the ship, encrusted with hard and soft corals and the occasional waving sea fan. Then, something unmistakable. A cannon. “We’ve got ourselves a warship,” Upali leaned back and smiled. I’d bet a round of beers that this is the Vampire.”

“We got very lucky,” said Suresh, not taking his eyes from the screen. “She’s literally hanging over a cliff. A few more feet to the north and this wreck would be in 2,000 feet of water.”

“A little beyond your diving depth, eh, machang?” Upali elbowed him in the ribs and laughed.

For the next several hours, they scoured the wreck with the ROV, methodically working from forward to aft, breaking for lunch and, later, some tea. By late afternoon, they still hadn’t found any evidence that positively identified this ship as the Vampire,