WHOI Joins NOAA in 3D Wreck Survey

During World War II, the seas off the coast of North Carolina were the site of a devastating period for the United States, during which dozens of ships, mostly merchant vessels, were sunk by German U Boats. The National Oceanic and Atmospheric Administration (NOAA) estimates that from January to August 1942 alone, more than 50 vessels were lost to the U-Boat assault. Together with Woods Hole Oceanographic Institute (WHOI), a 10-day mission to provide NOAA with the first 3D optical survey of the undersea wrecks off the Carolina coast is now underway.  

The cooperative venture, funded by NOAA's Office of Exploration and Research, will also employ a team of divers and archeologists from the National Park Service Submerged Resource Center, UNC Coastal Studies Institute and the Cooperative Institute for Ocean Exploration Research and Technology.

 "We hope to get a full 3-D picture of several sites so that NOAA can go back and assess the wrecks' condition and the impact of the ships on the marine environment," said Evan Kovacs, director of 3D photography for Woods Hole Oceanographic Institution's (WHOI) Advanced Imaging and Visualization Lab (AIVL). "We're breaking new ground."

"This is our first large-scale marine archeology program with NOAA," said AIVL director Bill Lange. Lange and his team have been conducting similar marine archeology programs with the National Park Service and State agencies over the last 5-6 years.

From a purely scientific perspective, the mission presents a unique opportunity, according to NOAA, which has dubbed the project The Battle of the Atlantic. "For the first time, these expedition scientists will study a maritime battleground off the coast of North Carolina, " according to NOAA officials.

The mission, currently in progress aboard the NOAA vessel SRVx, employs a remotely operated vehicle (ROV) outfitted with several underwater 3D and high-definition camera systems developed by Lange and Kovacs. Over the course of the survey, the ROV pilot will work closely with technical dive teams in surveying the wrecks previously identified by the side scan sonar survey. The NOAA NPS and WHOI teams expect to conduct these optical surveys and close up inspection task on targets as deep as 500-600 feet. The technical dive teams will utilise AIVL's smaller diver-operated underwater 3D and 2D imaging systems in order to acquire imagery that would be difficult for the ROV to accomplish.

The WHOI survey and mapping effort is the most detailed phase of the project, which is coordinated by NOAA's Monitor National Marine Sanctuary. Previous stages utilised a sonar system to provide a wide-area remote-sensing survey to give researchers a 'big picture' or birds-eye-view of the battlefield area.

NOAA then employed a multi-beam sonar system to "zoom in" on some of the wrecks for a closer look.

WHOI's mission will deliver what promises to be the most dramatic still and video images, which will provide the detailed data needed to fashion the large, two- and three-dimensional mosaic maps of the shipwreck sites.

"These videos will be used to create detailed pictures that researchers can use to monitor changes in that vessel over time" NOAA project officials say on their website. "The 3D videos will also make exceptional education and outreach tools. As a program that has dual responsibilities for both science and education, this system integrates perfectly with our program objectives," said Joe Hoyt, Principal Investigator for the Battle of the Atlantic Project.

Says Lange: "Using the imagery we collect on this expedition, we hope to work with NOAA in the future to create educational videos." A number of television documentaries are also in development to cover these expeditions.

Kovacs cautions that the mission is not without potential problems, primarily those generated from relatively deep waters and high currents that could affect the performance of the scientific instruments. "But," assures Lange, "we're very good at transforming work-class ROVs into sophisticated image platforms."

Using high-end deep submergence platforms, Lange and his AIVL colleagues have surveyed numerous high-profile wrecks, most notably the Titanic, as well as natural formations on the seafloor.

The WHOI researchers are particularly excited by their role in the Battle of the Atlantic project because of its potential to provide a first look at a critical piece of wartime history.  "They've known about some of these ships for decades," Kovacs said, but this will be the first time the site will be surveyed and mapped in such detail.

In addition, project researchers will be on the lookout for one of the last of the known German U-Boats, which has yet to be found.

The WHOI portion of the project is funded by NOAA and private sources, Lange said.

Image: the 3D equipment carried aboard. Image Courtesy: WHOI.