Capturing New Views of USS Monitor Through High-Resolution Ocean Mapping

January 29, 2026

More than 160 years after it sank off the coast of North Carolina, the ironclad USS Monitor continues to tell new stories from the seafloor. In September 2025, researchers at Monitor National Marine Sanctuary partnered with engineers from Northrop Grumman to complete the highest-resolution scan of the historic shipwreck ever conducted—producing detailed imagery, three-dimensional models, and other digital data products that will soon be shared with the public.

aerial view of a research vessel with a crane deploying equipment over the side — Northrop Grumman deployed the uncrewed underwater vehicle from their research vessel at Monitor National Marine Sanctuary. Reese Bland/NOAA

Discovered in 1973 and designated as the nation's first national marine sanctuary in 1975, USS Monitor rests nearly 240 feet below the ocean's surface, where it now functions as both a cultural resource and a thriving artificial reef. The sanctuary team regularly monitors the site to better understand how the wreck is changing over time and how marine life is using the structure. High-resolution mapping plays a key role in that stewardship, allowing scientists to document conditions without disturbing the fragile site.

Behind the Data

a gray uncrewed underwater vehicle sits on the deck of a research vessel ready for deployment — An uncrewed underwater vehicle outfitted with micro synthetic aperture sonar (µSAS) was used to map the USS Monitor wreck. Photo: Tane Casserley/NOAA

To support that work, the Northrop Grumman project team deployed a compact uncrewed underwater vehicle equipped with micro synthetic aperture sonar (µSAS), a system capable of producing detailed images even in low-visibility conditions. The survey captured fine-scale views of the wreck and surrounding debris field, as well as high resolution detail of components such as the vessel's keel. According to Monitor National Marine Sanctuary Research Coordinator Tane Casserley, "This is the first modern sonar survey that has provided this level of resolution of Monitor's hull remains and internal structure."

The resulting dataset includes high-resolution sonar imagery, environmental observations, and three-dimensional digital reconstructions of USS Monitor. "This incredible technology produces results with near-photographic resolution and extreme three-dimensional accuracy," proclaimed Casserley. "These products provide a valuable baseline for future monitoring and create new opportunities for education, research, and public engagement, particularly for those who may never have the chance to visit the sanctuary in person."

Using the scan data, Northrop Grumman generated detailed 3D models that support long-term documentation and interpretation of the wreck. Digital preservation tools like these allow researchers to track change over time while also helping the public visualize an iconic piece of American maritime history.

four men in lifejackets and helmets help carefully guide the uncrewed underwater vehicle suspended from a crane over the side of the research vessel — A deck crane is used to deploy the uncrewed underwater vehicle. Photo: Tane Casserley/NOAA

In addition to providing NOAA with valuable new data, the project offered the engineering team experience operating the technology in a novel field setting. The work aligns with Northrop Grumman's Technology for Conservation (T4C) initiative, which applies engineering expertise to conservation efforts.

Kevin Gallagher, a key engineer architect on the µSAS team, explains that while this technology has been used by Northrop Grumman on projects before, it has never been used in a way where the data was made publicly available. "For our µSAS team, this was an opportunity to show how we're using this high-res imagery and 3D tech beyond the aerospace and defense industry, growing our reach and capability of µSAS," Gallagher commented. "We were able to capture detailed images of the shipwreck and surrounding debris field, assisting NOAA in collecting biological data to further identify what species inhabit the area."

As a result, all data products from the project—including 3D models, visualizations, and animations—will be transferred to NOAA and made available for public use, supporting transparency, education, and long-term stewardship of the site.

Public Unveiling at The Mariners' Museum and Park

The new digital products will be unveiled during a public event on March 7, 2026 at The Mariners' Museum and Park, where visitors will be able to explore USS Monitor through interactive displays and visualizations. The event will highlight how emerging technologies are helping researchers study submerged cultural resources while expanding access to maritime heritage beyond the ocean floor.

By combining advanced mapping tools with NOAA's long-standing stewardship of Monitor National Marine Sanctuary, the project demonstrates how collaborative science can deepen understanding of historic shipwrecks while connecting science, technology, and maritime heritage.

Rachel Plunkett is the content manager and senior writer/editor for NOAA's Office of National Marine Sanctuaries