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Underwater Drones Take Archaeology to New Depths

ROVs have helped find theTitanic and many other lost ships

March 8, 2016

Drones don't just fly; they dive, too. Hercules, the remotely operated vehicle (ROV) above, hovers near the stern of the RMSTitanic during the 2004 joint NOAA-Ballard mission.
Center for Exploration/University of Rhode Island/NOAA Office of Ocean Exploration and Research
On Halloween night, 1780, the HMS Ontario struggled through rough waters on Lake Ontario. Strong hurricanes had plagued the Caribbean throughout the month, and the remnants of those systems had spun north and turned into a ferocious fall gale.

A 22-gun brig-sloop, the warship had been built and commissioned only months earlier to aid British control of Lake Ontario during the Revolutionary War. Bound from Fort Niagara to Oswego for a raid, it carried an estimated 120 people onboard, including British troops, camp followers — wives and children of soldiers — and American prisoners of war.

The Ontario and those 120 passengers would never make it to Oswego. Vicious northeast winds rose rapidly around 8 p.m., sweeping down the lake. Similar storms plague the Great Lakes each autumn, producing whiteouts, snowsqualls, and freezing rain; waves cresting over 35 feet and wind gusts over 80 miles an hour have been recorded. The Ontario ’s sails probably blew out — searchers found large sheets of torn canvas on the lake days later. The rolling waves and wind likely caused the ship to list, then take on water, the cannons and ammunition shifting violently. A few lifeboats, blankets, and personal gear were recovered, but little debris surfaced, suggesting the ship went down rapidly. Nine months later, six bodies washed ashore; no other trace of the Ontario was seen again.

Until 2008, that is, when Dan Scoville piloted his ROV Proteus 500 feet below the surface of the lake, filming the Ontario where it sits on the bottom, tilted slightly to port.

Scoville and fellow shipwreck enthusiast Jim Kennard had been searching for the Ontario for three years, using archival research and side-scan sonar to find a target for his self-built Proteus to explore.

“It feels pretty good,” he says. “You look for that thing for years, you spend days staring at the screen and driving the boat back and forth ... [And then] you’re flying around something that’s 230 years old, that hasn’t been seen since the day it sank, and it looks just like it did on the day it went down.” The Proteus’ video shows the Ontario ’s twin masts still standing, spearing out of the inky depths complete with crow’s nests. The ship’s bell is still in its belfry, cannons askew but still on the decks. The oldest wreck found in the Great Lakes, it’s remarkably intact.

Conventional scuba diving is restricted to a depth of 130 feet. Highly trained and experienced technical divers can exceed that by breathing specialized mixed gases and following a precisely calculated schedule of decompression stops while surfacing, but even those divers rarely try the depths where the Ontario sits. Exploration of its final resting place — and hundreds of other underwater archaeological sites worldwide — had to be unmanned.
Vehicles for the final frontier

There’s no shortage of acronyms in the world of unmanned vehicles. Those that operate below the surface of the water fall under the umbrella term unmanned underwater vehicles, or UUVs; the most commonly used UUVs are autonomous underwater vehicles (AUVs) and remotely operated vehicles (ROVs).

AUVs move beneath the surface of the water without continual input from a pilot, operating independently on a preprogrammed course. Often used for mapping or surveying, AUVs are not tethered to a ship, and return to a pick-up point once the mission is complete so data can be downloaded and processed. ROVs, on the other hand, connect to the surface via cables that bring signals from the operator and return data and images in real time. (Why the cable? While aerial technology like UAVs can fly without being tied to their pilots, radio waves do not travel well through water, necessitating the tether.)

ROVs like Scoville’s Proteus are ideal for getting a closer look at something under the water — navigation hazard identification, vehicle hull inspection, pipeline maintenance — and may carry tools far beyond a standard camera, including arms or manipulators that can cut, repair, and retrieve. Since the 1960s, the military has used ROVs for mine detection and neutralization, while they became essential to the oil and gas industry throughout the 1970s and ’80s for line inspection and repair.

The scientific community began to use ROVs in that timeframe as well, largely for observation and specimen collection. Brett Seymour, deputy chief of the National Park Service’s Submerged Resources Center (SRC), says the first in-person interaction the SRC staff had with an ROV was in the 1980s, when National Geographic brought one to Isle Royale National Park. At the time, the technology was bulky and expensive; since the agency mostly works in calm inland waters off small boats, they bided their time, waiting for an ROV with a smaller footprint. By 2000, the platform had matured, and the SRC purchased their first observation-class VideoRay.

Kate McGarry, marketing coordinator for the Pottstown, PA-based VideoRay, says the company saw growth on a similar timeline, entering the field as one of the pioneers of small observation ROVs about 15 years ago, and continuing to expand and develop its capabilities. In the last five years, she says, the market has seen “an explosion in small ROV use on a global scale.”

Able to travel much deeper than a human diver and stay down for much longer without concerns about air or decompression, ROVs now see deployment in not just industry, military, and natural-resources research, but in law enforcement, homeland security, and maritime archaeology. In fact, ROVs began to seep into the public consciousness in large part because of the work of underwater archaeologists and explorers like Jacques Cousteau, Robert Ballard, and James Delgado.

Cousteau, of course, was famous for his improvements in scuba technology, pioneering underwater expeditions, and television documentaries. Though a part of countless oceanographic advancements, Ballard garnered the most public acclaim when his team found the final resting place of the RMS Titanic, 12,500 feet deep in the North Atlantic. In 1986, his team explored the wreck using the deep submergence vehicle (DSV) Alvin and the ROV Jason Jr., the infamy of the Titanic drawing wider attention to ROVs and their use. Delgado, currently the director of maritime heritage for the National Oceanic and Atmospheric Administration’s (NOAA) Office of Marine Sanctuaries, has been a part of archaeological shipwreck expeditions around the world, including the Mary Celeste, Pearl Harbor’s USS Arizona, and recent work on the Titanic.

“What the ROV is doing is giving us a look where no one’s looked before — so it’s Star Trek,” he says. “This is really the final frontier.”
The Hercules and the Argus are shown hovering over the Titanic 's stern. Tethered to and operating in tandem with Hercules, the Argus the acts as a stabilizing platform, supplies extra light, and allows pilots to view Hercules in the water. Center for Exploration/University of Rhode Island/NOAA Office of Ocean Exploration and Research
Did You Know?
ROVs can travel much deeper than a human diver and stay down for much longer without concerns about air or decompression.
A deep dive

ROVs are categorized into classes based on size, depth capacity, and horsepower; as with any tool, the right ROV for the archaeological job is dependent on the environment and the goals of the project.

Going down — like way, way down? Work-class ROVs, like the one used as part of the 2007 “Mardi Gras” shipwreck project in the Gulf of Mexico, dwarf their operators. Huge, heavy, and expensive, the minivan-sized ROVs can be equipped with a variety of manipulators and go to depths of 10,000 feet or more. A smaller ROV might sound more agile and therefore easier to drive, says Mark Gleason, an ROV pilot and an assistant professor specializing in marine education at Michigan’s Grand Valley State University. But the heft of the work-class ROVs helps keep them on course when tugged about by strong ocean currents in deep-water environments.

In the case of the Mardi Gras shipwreck — named after the nearby oil and gas pipeline system — the mystery ship rested 4,000 feet below the surface, off the shore of New Orleans. It was, at the time, the deepest wreck explored in the Gulf.

Led by Texas A&M University with a team of more than a dozen archaeologists, plus a film crew, ROV pilots, and support staff, the Mardi Gras project’s goals were to record the site and recover artifacts for analysis. Work was underway 24 hours a day, live-streaming to a bullpen of monitors on the ship so several sets of eyes were always on the work being performed.

Because recovering artifacts was a primary goal, the project’s work-class Triton ROV was modified to wield unique retrieval tools: a suction package with a filter, baskets and containers, shovels and brushes, pincers, and claws. It was painstaking work — archaeologists aboard the ship relayed instructions to the ROV pilots, who then had to perform the delicate maneuvers to pluck, scoop, or suck coins, buttons, tools, dishes, bottles, sand-glasses, weapons, and even the ship’s stove from the ocean floor.

“Not one artifact was destroyed,” says Peter Hitchcock, who was involved as part of A&M’s Department of Oceanography. “That’s pretty remarkable when you consider the glass and china we recovered.”

Still, “most archaeology is tactile,” notes nautical archaeologist Ben Ford, part of the project’s team through A&M’s Department of Anthropology. “You handle artifacts, rotate them, squint at them, look at them under microscopes.” To watch in 2D as the artifacts were recovered was tricky, he says, as was relaying all his thoughts and directions to the ROV pilots rather than performing the actions himself.

Hitchcock disagrees. “It’s not really different,” he says. “Every shipwreck has a story, and you want to know what it is. The ROV is simply a tool to get to the artifact to get to the story.”

And the Mardi Gras ship’s story?

The artifacts the ROV recovered were traced to manufacturers in Great Britain, France, Mexico, the U.S., and Germany, and dated; based on the age and availability of the items on board, researchers placed the wreck between 1808 and 1820. More importantly, the project gave the team an opportunity to experiment with the ROV as a deep-water archaeological tool.

“As nautical archaeologists, we realize more and more that the tools ocean explorers were using, we could use too,” Hitchcock says.

“Every shipwreck has a story, and you want to know what it is. The ROV is simply a tool to get to the artifact to get to the story.”
Time capsules on the bottom

Shallower waters call for different tools to meet different goals.

Observation-class ROVs rarely exceed depths of 1,000 feet. Lighter, smaller, and less expensive than work-class ROVs — think 15 pounds, rather than 300, and several thousand dollars, rather than several hundred thousand — observation-class ROVs are more suitable for launching off small vessels. As their name suggests, these vehicles are generally intended for observation, rather than retrieval, and while they may be equipped with cameras, sensors, and sonar, wield fewer manipulators.

Observation is the name of the game at the archaeological sites in the Great Lakes. Big names like the Titanic and huge ocean operations like the Mardi Gras project get much attention, but the Great Lakes draw maritime archaeologists and shipwreck enthusiasts from around the world in increasing numbers. The fresh water and low temperature — even in the summer, the water below the surface rarely climbs above 40 degrees — preserve shipwrecks almost perfectly, marred only by zebra and quagga mussels, for decades or even centuries.

“You can explore a wreck in Lake Superior that’s been on the bottom for 100 years and still see the name painted on the ship,” says Kevin Cullen, president of the Wisconsin Underwater Archeology Association (WUAA). “They’re time capsules.”

On the SS Kamloops, one of the graveyards of wrecks that circle Lake Superior’s Isle Royale National Park in Michigan, nearly 90 years in 270 feet of water hasn’t disfigured cargo from the final voyage: Crates of shoes and the wrappers of Lifesavers candies still look nearly new. That level of preservation means that while archaeologists and ROV operators on the Mardi Gras project sifted through splintered remains of the ship, recovering concretions — conglomerate lumps created by natural elements forming around artifacts — and encrusted artifacts, wrecks sitting on the bottom of the Great Lakes allow archaeologists to study ships as a whole.
The Hercules ROV gently recovers a medicine bottle filled with ginger, a seasickness remedy, from an early 19th century shipwreck in the Gulf of Mexico.
Ocean Exploration Trust/TSU Meadows Center for Water and the Environment
The goal is to document, Cullen says, to look at a wreck in place on the bottom, and to leave the artifacts down there. “Unlike what we think of with archaeology, there’s no excavation — we document as it lies in place.” Simply moving artifacts is discouraged, because not only what the artifacts are, but where they are can tell archaeologists a lot.

While WUAA uses observation-class ROVs to document, other organizations use them to survey the field before divers are sent in. The National Park Service’s SRC, for instance, employs ROVs as a precursor to diving operations to help their staff understand what the site looks like, or to maneuver in spaces that would be unsafe for divers. In the wreck of the USS Arizona in Pearl Harbor, for instance, the SRC used an ROV with an attached environmental sonde to survey the interior compartments of the battleship and evaluate hull corrosion rates and dangers due to oil leakage.

Other groups use ROVs in concert with AUVs or side-scan sonar to locate and identify new wrecks. AUVs and side-scan are the “tech of discovery,” Cullen says, while “ROVs are the tech of confirmation and analysis.” Those employing ROVs in the search for new wrecks range from trained career archaeologists to individual enthusiasts, like Ontario-discoverers Scoville and Kennard, to volunteer organizations like WUAA.

Valerie van Heest says the accessibility of ROVs has allowed her group, the Michigan Shipwreck Research Association (MSRA), to search out and document deeper wrecks. A nonprofit dedicated for the past 20 years to searching for and educating the public about shipwrecks on the eastern side of Lake Michigan, MSRA doesn’t own an ROV. Instead, it pinpoints wreck sites with its sonar, and then links with ROV-equipped organizations to investigate. In the July 2015 discovery and documentation of the wreck of the John V. Moran, for instance, MSRA worked with the Michigan State Police and its ROV. The arrangement was mutually beneficial: MSRA was able to document the steamer, which wrecked in 1899 and now sits in 365 feet of water, while the Michigan State Police had the opportunity to test its equipment at depth, and showcase its underwater abilities and equipment to the public.

The excitement of seeing wrecks like the Moran on the ROV’s camera is phenomenal, van Heest says. “I was sitting next to the ROV operator. I had a photo of the ship in my hand, and I could make an immediate positive ID — the ROV actually came down at the exact perspective of the photo. It’s so exciting and surreal in terms of history,” she says. “Most people just read about it; I’m seeing the real thing.”
A VideoRay ROV examines the windlass deck machinery of the America shipwreck located in Washington Harbor of Isle Royale National Park. NPS Submerged Resources Center
Training, Tools, and Rules

Unlike aerial drones, few regulations govern use of ROVs. Instead, their use is covered under the laws that manage shipwrecks and divers. The Abandoned Shipwreck Act of 1987, for instance, specifies that shipwrecks in state or federal waters belong to the government that controls those waters; no one may salvage or remove items from those wrecks.

Beyond governance of such sites, being a good ROV pilot really comes down to situational awareness, Cullen says.

Gleason, who has instructed over 30,000 students in the design and creation of ROVs over the last 10 years, agrees. A good ROV pilot has two main qualities, he says: adaptability, because they often work in a variety of awkward environments with a range of individuals and personalities, and problem-solving. “Remember that driving an ROV is just part of the story,” he says. “The real story is how do you make the ROV work when it’s broken. And believe me, it will break down. The underwater world is not kind to electronics … Those will be the moments that the pilot will wish they had more training."

College programs in both marine technology and marine archaeology make such training available across the country, including at Alpena Community College, where Gleason is an instructor. And competitions like MATE (Marine Advanced Technology Education) challenge grade school and high school students to build their own ROVs, stimulating interest in both robotics and marine exploration. It’s a beneficial cycle: Students can learn how to use ROVs, and using ROVs can in turn teach them much more about robotics, marine biology and oceanography, history, and archaeology.

Cullen sees ROVs as archaeological tools with a utility beyond exploring and documenting sites. “It’s really about [their] ability to educate and build relationships with the community,” he says. WUAA’s “Eyes in the Deep” program, for instance, launched an ROV to the carferry Milwaukee and the schooner Rouse Simmons, involving the public in documenting the underwater topography and creating photomosaics.

“The impact of the public seeing the bunkbeds inside the Milwaukee ’s crew quarters, or the pine trees in the Rouse Simmons, and sharing that experience in real time, is huge,” Cullen says.

Other underwater explorers, maritime archaeologists, and shipwreck enthusiasts have known similar moments. In 2012, NOAA’s Delgado was a member of the Monterrey shipwreck survey in the Gulf of Mexico. Their work-class ROV, Hercules, retrieved about 60 artifacts from depths of 4,300 feet, including muskets, bottles, ceramics, and navigational instruments — all while a livestreaming feed was available for public viewing. It was the first time, Delgado recalls, that the public was able to watch live and participate in such a project. “That was pretty powerful,” he says, because education is always a goal no matter what a project’s focus might be.
“ROVs turn the lights on in a darkened room."
Turning on the lights

But the most exciting part, Delgado adds, is what’s next.

Wireless and acoustic communication systems, not limited by the impenetrability of water to radio waves, allow for untethered ROVs — a game-changer, if the technology can be refined to provide reliable and high-quality data reporting without a cable. Already hybrid AUV-ROVs (HROVs) are being used by agencies on the cutting edge, like the Woods Hole Oceanographic Institute. On a smaller scale, Cullen and van Heest are eager for higher resolution cameras and other “elite” features to trickle down to the observation-class ROVs, and hope for ROV-mounted measurement and mapping systems for surveying wrecks. And as prices fall, more hobbyists will be able to purchase their own ROVs.

The growing number of ROV hobbyists doesn’t worry Cullen. “The more the merrier,” he says. “Recreational users can be like an extra toolkit. With the proper advocacy, they’ll help create an archive.” Whether for documentation, education, or artifact retrieval, the utility of ROVs as archaeological tools is clearly blossoming.

“The technology is such that we’re really seeing unparalleled access,” Delgado says. “ROVs turn the lights on in a darkened room."

Note: A version of this story appears in the Drone360 March/April 2016 issue
Featured image: Brett Seymour/NPS Submerged Resources Center