An underwater ultrasonic device includes a curvilinear ultrasonic transducer and a plurality of straight linear ultrasonic transducers. The straight linear ultrasonic transducers are disposed with respect to the curvilinear ultrasonic transducer. A first angle is included between the straight linear ultrasonic transducers. One of the curvilinear ultrasonic transducer and the straight linear ultrasonic transducer is configured to transmit a plurality of ultrasonic signals. Another one of the curvilinear ultrasonic transducer and the straight linear ultrasonic transducer is configured to receive a plurality of reflected signals of the ultrasonic signals.