The need to patrol the underwater of the United States coastlines is growing. There are many different public safety applications for underwater sonar technology. While used mainly for body recovery, recovering wreckage, and imaging underwater evidence fields, other applications can range from intercepting drug smuggling to public infrastructure inspections. Since its invention and usage beginning halfway through the 20th century, some key trends improving underwater sonar include greater portability, expanded image resolution, and enhanced procession capabilities for incoming data. Side-scan and scanning sonar are the two main sonar technologies. Advanced sonar technology enables dive teams to know exactly what lies deep beneath the murky and turbulent waters and pinpoint the location of evidence for a quick recovery, and make the dive much more efficient and safe for the divers. Sonar has revolutionized the way public safety diving is conducted, and made it far more productive and safe.