Digital Extra: Mountains in the Sea

NOAA

The ROV Hercules on the deck of the NOAA ship Ronald. H. Brown.

Every minute or so, the foghorn blasts. The ship, on an overnight haul toward Manning Seamount, climbs a swell, then slides down the other side, swaying. The anchors that hang against the bow crash into the hull with a sound like a car wreck.

Every ten seconds, the multibeam mapping sonar chirps, like a very loud sparrow trapped in an echo chamber. Motors, generators, bow thrusters add to the cacophony.

Sleeping in my narrow bunk, I'm frequently jarred awake. Here below waterline, there's no way to tell midnight from dawn, so I check my indiglo watch. It's 1:30, then 3, then 5 something, then the alarm goes off at 7:30 to start another day.

We woke today to a new sea.

Late last night, as we plowed through the fog, Peter Auster had clued us in that this was coming. "We'll be crossing the Gulf Stream tonight," he said. "Then the fog will lift, and it'll get warm, and we'll be basking on the bow in shorts and t-shirts!"

He flung his arms wide to simulate the anticipated sprawl. Sure enough, today the sky is clear. The ocean has lost its gray-black sheen, and glows a deep irridescent blue. The air feels warm and mild, and the ship's bow wave sparkles a brilliant white.

Out on deck, the ROV crew spent the day of travel time meticulously checking and tweaking their machines. About 8 p.m., Jim Newman, chief engineer for the Hercules team at University of Rhode Island's Bay Campus, came into the science lab to tell lead scientist Les Watling to expect a delay -- the pre-dive checks found a hose that needs replacing, and it will take an extra hour or so. Everyone takes in stride such last-minute changes, it's the rule of life on the ocean, where waves and weather, equipment problems, can't be predicted, and nothing is ever certain.

NOAA

The light-bearing camera sled ARGUS, also on the deck of the Ron Brown.

It's the unknown possibilities that Newman finds troublesome. "It's those things that I'm not worried about, that worry me the most," he said. The problems he can foresee, he can forestall. "But the other day, with the carbon buildup on the wires, who could have predicted that?"

So they do what they can, and hope for the best.

This is only the second cruise for Hercules. (Its first deployment, in the Black Sea last summer, is written about in this month's National Geographic magazine.) At about 8 feet tall, and weighing as much as a large car, it's an impressive device. Its yellow top consists of a high-density foam to provide buoyancy. On the front, two robot arms are installed, one for precise and delicate manipulation -- called the Predator -- and one for brute strength -- called Mongo. Bolted between the two arms is the insulated biobox, with a drawer that opens and closes hydraulically. The box fills with cold water at the sea bottom so the creatures collected there can travel comfortably to the surface.

Around the frame are stowed thrusters to drive it and hold it in position. "We can control any direction except pitch and roll," Newman said.

Hercules is designed to always stay upright and steady. The frame also holds an array of lights and sensors: a bubblecam that can swivel in any direction, high-powered 400-watt lights, high-definition video cameras, an acoustic scanning sonar. "The sonar paints a picture for the pilot of the surroundings, beyond the 30-foot reach of the lights," Newman said.

Hercules -- aka "Big Herc" -- is tethered to Argus, the tow sled, with a hundred-foot neutrally buoyant cable. Argus dangles beneath the ship on a strong steel cable that winds onto a huge winch bolted to the aft deck. The cable encases the wires that deliver power to both units and the wires that carry data back to the ship. Argus has thrusters on board so the pilots can control its orientation, and keep it pointed toward Hercules, but it doesn't provide any propulsion. It acts as a kind of shock absorber, protecting Hercules from the jerks and heaves of the ship.

With Argus as a mediator, Hercules can work in peace, as long as the line that connects the two remains slack.

Argus also carries two 1,200-watt lights and a tiltable high-definition video camera. Both vehicles carry navigation beacons that send a pulse of sound back to the ship, to relay their precise position. Later in this cruise, the two ROVs are scheduled to dive to 4,000 meters, the deepest they've ever been.

What's next for the pair after this trip, and their Titanic visit in June?

Newman said that's all that's planned for this year. "Bob [Ballard] has me working on an autonomous vehicle next," he said. "That way the ROV can go off on its own, while the ship is doing other things. It will make better use of the ship's time."

At about 10 p.m. Thursday, we are getting close to Manning Seamount, the farthest point out of our trip, and the ROV team is almost ready to deploy. It will take about an hour or two for the vehicles to sink to the seafloor. All night, the science team will stand watch as the ROVs sink to the bottom and explore.

Early Friday morning I'll join them in the control center to take a shift observing the live video, and my log next Monday will describe that experience.