When archaeological secrets lie far below the ocean's surface, how do historians and archaeologists know where to look? They work hand in hand with archaeological oceanographers like Katy Croff.

"I use tools, techniques, and research from oceanography, as well as from my background in geology, to help archaeologists make discoveries," Croff says.

Days in the field are intense. Weeks or months aboard research ships are marked by close quarters, unpredictable sea conditions, and an ever ticking clock. "Ship time costs thousands of dollars a day, so every second counts," Croff says. "We work in shifts to collect data 24 hours a day, but even when you are 'off,' there's much to do. We typically work day and night with very little sleep."

Croff's role varies day to day and voyage to voyage. Her skills include navigation, remote survey operations, engineering, scuba diving, and educational outreach. This diversity "is important on research cruises," she says. "Since we have a limited number of engineers and scientists, every bit of knowledge counts."

In 1999 Croff joined a research expedition led by Robert Ballard to the Black Sea. Approximately 7,000 years ago there was a rise in sea level of about 500 to 660 feet. "We surveyed this depth range to see if an ancient coastline and submerged habitation sites could be found," she says.

The team was also interested in these waters because oceanographic data had revealed a lack of dissolved oxygen needed to support marine plants and animals below depths of about 500 feet. The absence of those organisms, which eat organic material including ship's wood, improved chances of finding extremely well-preserved wrecks or other organic artifacts.

That knowledge, along with a comprehensive map Croff's survey team produced, helped locate four shipwrecks, each approximately 1,500 years old.

Croff has also worked with colleagues from the University of Rhode Island and Greece to undertake a project in the international waters off the Sea of Crete. Using her knowledge of the geological evolution of the sea, the project worked to predict where undiscovered archaeological sites might be found.

"This region is very active geologically," she says. "Studying sedimentation, tectonics, and volcanic activity, for example, will help show where sites are likely to be preserved—or destroyed.

"The University of Rhode Island's Inner Space Center is another very exciting project I'm involved with," she says. "It is literally revolutionizing how marine science is undertaken and shared with the public."

The center uses satellite technology to send data collected at sea back to shore, where an unlimited number of scientists can follow ship activity and communicate with the crew in real time.

Croff's passion for the sea and aptitude in the sciences led her to earn a bachelor's degree in ocean engineering at the Massachusetts Institute of Technology in Cambridge. She went on to get a master's degree in maritime archaeology at the University of Southampton, U.K. She is currently pursuing a Ph.D. in oceanography at the University of Rhode Island's Graduate School of Oceanography.

What's on the horizon? Croff hopes to have long-term involvement with the Sea of Crete survey. She also hopes to bring her passion for science and exploration to the public and the next generation of scientific leaders. "Days at sea are long and demanding, but it's those challenges and the teamwork that make it exciting," she says.