In most cases, the main objectives of search operations in the waters are the search for sunken or flooded objects with sizes from tens of centimeters to hundreds of meters at the bottom and in the water column (ships, boats, boats, cars, military and civilian equipment, structural elements and components, equipment, ammunition, etc.). The size of the waters can be small (pond, lake, canal, channel, river, etc.) and have a large area (large lakes and reservoirs, shelf seas and oceans).
The work is carried out using mobile sonar systems in the configuration of SSS, DSSS or SSSE, the area method of shooting (review) of the bottom is used. Depending on the type of water body and the size of the object, the operating frequency of the complex is selected, which in turn affects the received resolution in range (from 1 to 10 cm).
Search works allow:

• get acoustic 2-D image of the bottom and search objects (similar objects)
• to determine the geographical coordinates and depth of the objects of interest (goals)
• assess the state of objects and the bottom relief at the site of the object
• estimate the geometric dimensions of unknown objects

As a result of the search operations, the location of search objects or similar objects is determined, the target designation is given to the diver for descending to the object, lifting the object, etc.
The result of search operations can be positive - detection of objects of interest, or negative - objects are not found or found similar objects or goals that require additional work (technology) for their identification (diver descent, underwater video, trawling, etc.).

SEARCH EQUIPMENT:
Search complexes
Examples:
Underwater archaeology. What mysteries lie in the depths of the sea.
Underwater archaeology
Research Byzantine ship X-XI centuries. Balaklava (Sevastopol, Crimea)