Sonar has a great detectable range up to 1,000 meters compared with other common detectors. Therefore, when equipped with sonar, it will help the ships detect the fishes more exactly; reduce costs of fuel in the process of finding fishes. Specifically such as: allowing the tunny-net fishing initiatively catches fish by day and by night, combines many catching forms; helping captains be able to detect fishes in all directions, angles around the ships and fishes in a great distance. At the same time, appraising relatively feature of fishes, density, depth, direction of moving, moving speed… allowing to estimate the output through signals on monitors and have decision of encircling to catch or not, from there saving labor, increasing hauls of catching fish during the day; helping the captains observe clearly waters and substance of seabed, discriminate between signal of fishes and coral reefs, limit the danger for fishing-nets and boats…

According to the report of the Encouraging Fishery Center about applying sonar in exploitation of fish brought high effective. However, when taking sonar into operation, the protection of aquatic products source of income must have sanctions in order to exploit the resources strongly.