An ultrasonic probe comprising a housing, a first ultrasonic transducer array, a second ultrasonic transducer array, a first light source, and a second light source. The first ultrasonic transducer array is coupled to the housing and configured to emit a first planar ultrasonic beam in a first direction within a first plane. The second ultrasonic transducer array is coupled to the housing and configured to emit a second planar ultrasonic beam in the first direction within a second plane, which is substantially perpendicular to the first plane. The first light source is coupled to the housing and configured to project a first light line substantially within the first plane. The second light source is coupled to the housing and configured to project a second light line within a third plane, which is substantially perpendicular to the first plane and intersects the second plane at an oblique angle. The first light line intersects and is substantially perpendicular to the second light line.