The U.S. Office of Naval Research has awarded Rutgers University a grant to develop a drone equally adept at flying and navigating underwater. The craft could speed search-and-rescue operations, monitor the spread of oil spills and help the Navy defuse threats from underwater mines.

Javier Diez, associate professor in the Department of Mechanical and Aerospace Engineering, had been working with the concept for years. When he demonstrated a prototype of the "Naviator" to Navy research officials early in 2015, they agreed to fund work on new versions of the air-and-water craft.

The "Naviator" emerges from underwater. Image credit: Rutgers University.“There are birds that dive into water and fish that fly,” he says. But that comparison breaks down quickly.

“Waterfowl are still better at flying than swimming, and flying fish are still better at swimming than flying. Our device is equally adept at both,” he says.

Diez says that much work needs to be done before the prototype is ready for operational use. For example, the models that he and his students have demonstrated are tethered by a wire to a controller, because typical radio signals can’t penetrate water. To cut the cord, engineers will study ways to control vehicles acoustically—with sound pulses instead of radio waves.

By summer 2016 the researchers plan to demonstrate a vehicle that can swim in a seawater environment and do complex maneuvers, he says. “At that point, we’ll start to outfit it with whatever sensors the Navy wants to have, such as cameras and sonar detectors.”

Diez says the drone has many potential applications. For search and rescue, for instance, the vehicle could scan the water from above to locate missing swimmers and sailors and, upon spotting debris, could dip underwater to further examine the scene. At an oil spill site, it could map the spread of a spill and see how deep the oil plume reaches.

An air-and-water drone also could help engineers inspect underwater structures, such as bridge and dock piers, ship hulls and oil drilling platforms.