As the search continues for Sarah Majoras of Lambertville, officials continue to focus on a canal area near the Delaware River that's close to where the woman lives.

Surveilliance photo of Sarah Majoras crossing the bridge from New Hope, PA into Lambertville the nigtht of her disappearance. (Hunterdon County Prosecutor's Office)

For the second day in a row, marine police spent several hours checking the canal with sonar.

"They're basically looking for anomalies to show up on a screen so that our divers can verify as to whether there is a subject in the water - they will do every attempt to make sure they have what they're looking for - they'll verify with a camera and then we'll have to sometimes verify it again with a diver," Sgt. Steven Groseibl, Assistant Commander of the New Jersey State Police Technical Emergency and Mission Specialists Unit, said.

He says the sonar is a tremendous help, but it's not an exact science, because, "You can basically make out the size of something and then measure it on the screen but nothing is very clear…They'll be looking for any kind of anomaly that's on the screen that might be the approximate size of a human being around 5 foot…and then we would put the underwater camera in and or divers in to verify that anomaly on the screen."

Groseibl adds the operation will proceed "until the troopers are satisfied the area is clear- they may continue for several days… It's usually a difficult operation and the guys are working very hard."