Hydra systems, depending on the type, use the following basic technologies of sonar survey:

- Side scanning (linear 2-D scanning from a moving carrier to obtain an acoustic image in a certain capture band). It is realized with the help of side-scan sonar (SSS).
- Hydrolocation of the circular view (circular 2-D scanning from a fixed carrier to obtain an acoustic image in a certain radius of capture). It is realized with the help the lock around sonar (LAS) or SSS with the option of LAS.
- Echo-soundings (linear scanning with a moving carrier to obtain the point cloud of the depths below the carrier). It is realized by echosounder (ES) which is an option for SSS or is a part of ISSS.
- Areal bathymetry (linear 3-D scanning from a moving carrier to obtain a cloud of depth points in a certain capture band). Is implemented using interferometric side-scan sonar (ISSS), also performs the function of SSS and ES.
- Bottom profiling (linear scanning from a moving carrier to obtain an acoustic profile of the bottom structure under the carrier). Implemented using parametric profiler (PPF), also performing the function of ES.

In one complex it is possible to combine several technologies that can be used simultaneously or separately. For example:
- technology of echosounder measurements with instrumental estimation with the help of SSSE combines SE soundings and side scanning;
- the technology of areal bathymetry with ISSS allows you to simultaneously perform the functions of SSS, ES.