Marine archaeologists study human history by investigating sites preserved underwater, from centuries-old shipwrecks to prehistoric landscapes swallowed by rising seas. Their work spans fieldwork beneath the surface, high-tech remote sensing from research vessels, laboratory conservation of fragile artifacts, and detailed reporting that pieces together how people lived, traveled, and traded. It’s a career that blends the physical demands of professional diving with the analytical rigor of academic research.
Finding Sites Before Diving on Them
Most marine archaeology projects begin not with a dive but with remote sensing from a boat. Archaeologists tow instruments through survey areas to build a picture of what lies on and beneath the seafloor. Side-scan sonar sends thousands of sound pulses toward the bottom, then assembles an image based on the strength and timing of the returning echoes. This reveals objects sitting on the seabed, like hull remains or debris fields, without anyone getting wet.
Marine magnetometers detect distortions in Earth’s magnetic field caused by iron. Because historical ships used iron in their fasteners, rigging, and sometimes entire hulls, a magnetometer can flag a buried wreck that sonar might miss entirely. For even deeper investigation, a sub-bottom profiler sends sound waves that penetrate sediment layers and return a cross-section image of what’s buried underneath. This tool is especially useful for locating ancient river channels, flood plains, and other landscape features that were dry land thousands of years ago before sea levels rose.
What Happens on a Dive Day
Once a site is identified, divers go in. The first dive is typically a reconnaissance pass: locating the site, assessing visibility, and observing the current condition. That might mean a scatter of loose artifacts across the seabed, a recognizable wreck structure, or even the remains of a crashed aircraft.
Subsequent dives get more hands-on. Divers clear marine growth from surfaces, take scaled photographs, sketch and measure features, and catalog individual finds. A major goal is photogrammetry, where overlapping photos taken from multiple angles are later processed by software to generate precise 3D models of the site. This technique is particularly valuable in deep or difficult environments, because it lets archaeologists spend a short window capturing images underwater and then do the detailed mapping and drawing work later on dry land. Control points placed around artifacts allow the software to triangulate positions and plot objects in three dimensions that would otherwise be nearly impossible to measure by hand.
Excavation underwater relies on specialized tools. Airlifts, essentially large suction tubes, use compressed air injected at the base to create a flow that pulls loose sediment up and away from artifacts. A water jet at the cutting end helps break up compacted material. By adjusting the ratio of air to water, divers control suction strength so they can remove sand and silt without damaging fragile objects beneath. It’s slow, careful work, more like using a dental pick than a bulldozer.
Back on shore at the end of a dive day, equipment is organized and prepped for the next morning. Any data collected, photos, measurements, sonar files, is downloaded, checked, and processed immediately to catch gaps before the team loses access to the site.
What Marine Archaeologists Actually Study
Shipwrecks get the most public attention, but they represent just one category of underwater site. Marine archaeologists also investigate drowned prehistoric sites, places where ancient humans once lived on dry land that is now submerged. These can include campsites, tool-making areas, and burial grounds dating back thousands of years. Other site types include underwater refuse deposits (essentially ancient garbage dumps that reveal daily life), structures built directly in or over water like 17th-century wharves and historic lighthouses, and sites displaced from their original location by erosion or storms.
Aircraft crash sites from wartime are another significant area of work. These sites often carry legal protections as war graves, and archaeologists approach them with the same care and documentation standards as any other historically significant find.
Conservation After Recovery
Pulling an artifact from the sea is only the beginning of preserving it. Waterlogged wood, one of the most common finds on underwater sites, poses a particular challenge. If degraded wood is simply allowed to dry, it collapses as water leaves the cells, shrinking and cracking beyond repair. The standard treatment involves replacing the water in the wood with polyethylene glycol, a waxy substance that fills and stabilizes the cell structure. Even after treatment, keeping free water away from preserved wood remains critical, because residual moisture encourages microbial growth and further degradation. Before conservation begins, waterlogged artifacts are best stored in oxygen-free conditions, since most bacteria and fungi need oxygen to break down wood.
Metal artifacts corrode differently depending on whether they sat in saltwater or freshwater, and each material requires its own stabilization process. Conservation work can take months or years for a single object, and it represents a significant portion of the time and budget on any excavation project.
Reporting and Legal Protections
Every project ends with a detailed report. Data collected in the field forms the basis of documents submitted to clients or national archaeological curators. These reports typically include site assessments, condition evaluations, and recommendations for next steps: whether a site should be preserved in place, recorded and left alone, or have artifacts lifted from the seabed for conservation.
This work operates within a strict legal framework. The UNESCO Convention on the Protection of Underwater Cultural Heritage establishes core international principles, including cooperation between nations, respectful treatment of human remains found in maritime waters, and encouragement of non-intrusive public access to underwater heritage when it doesn’t conflict with site protection. In practice, marine archaeologists must secure approval for their methods from archaeological curators before fieldwork begins, and they follow professional standards for conservation and long-term site management throughout and after a project.
Where Marine Archaeologists Work
Employment spans several sectors. Universities and colleges hire marine archaeologists as faculty and researchers. Federal, state, and local government agencies employ them to manage cultural resources in public waters. Museums, historical societies, and restoration programs bring them on for specific collections or site projects. A large share of the work happens in private archaeological consulting firms, where marine archaeologists conduct environmental impact assessments for construction, dredging, or offshore energy projects that might disturb underwater sites.
The U.S. Bureau of Labor Statistics groups marine archaeologists with anthropologists and archaeologists broadly. The median annual wage for this category was $64,910 as of May 2024, with the lowest 10 percent earning under $44,510 and the highest 10 percent earning above $104,510. Federal government positions pay the most, at a median of $89,460, while university positions average around $57,010. Employment is projected to grow 4 percent from 2024 to 2034, roughly matching the average for all occupations, with about 800 openings expected per year across the field.
Education and Training Requirements
Marine archaeology requires both academic credentials and physical diving qualifications. Most professional positions call for at least a master’s degree in maritime archaeology, anthropology, or a closely related field, with a PhD typically needed for university teaching and senior research roles. Coursework covers archaeological theory, research methods, artifact analysis, conservation science, and maritime history.
On the diving side, marine archaeologists train to meet standards set by organizations like the American Academy of Underwater Sciences. University programs such as the one at the University of Rhode Island offer dedicated research diving courses that combine open-water skills with archaeological field methods. Beyond basic certification, many projects require advanced diving qualifications including mixed-gas diving for deeper sites, experience with underwater photography and videography, and proficiency with the remote sensing equipment used during survey phases. The combination of postgraduate education and professional dive certification makes this one of the more demanding career paths in archaeology to enter, but also one of the most distinctive.