The Different Processes Involved in Hydrographical Survey

A branch of applied science, Hydrography is associated with the scientific measurement and description of physical attributes of the water body comprising seas, lakes, rivers and oceans. Thus a hydrographical survey can be stated as an activity performed mainly for evaluating the factors that lie beneath the water for the special purpose of navigation. Such surveys are conducted by the civil engineer’s under-recognised authority for the purpose of defining shoreline and underwater characteristics of the water body.

Since such surveys are conducted by experts; it is advisable to hire the services of reliable hydrographical survey Company in India. The survey is utilised for ensuring safe navigation of different water bodies by marine vessels. In addition to this, it facilitates in checking the potential of the water body for activities associated with resource exploitation, drilling and offshore oil and gas exploration. Some hydrographic surveys also aid in the preparation of charts and maps to create secure shipping lanes.

Application of Hydrographic Survey –

• One of the most popular applications of hydrographic surveys is to determine the depth of the sea for the purpose of creating safe shipping lanes along the ocean or river.

• With the help of surveys, shore lines can also be determined for ensuring safe tourism and undertaking activities like recreational boating.

• Such surveys help considerably in measuring the momentum and magnitude of the tide that helps perfectly in creating a danger zone for safety purpose.

• Surveys are used to determine the suitability of the sea bed and its soil holding capacity for a building of bridges, dams as well as harbours.

• Experts also indulge in conducting surveys for the purpose of evaluating the flow and direction of sea current for directing the location of sewage water pipes.

Steps involved in Hydrographic surveying –

The process of survey starts with by finding special control points along the line of the shore. Sounding is one of the most important exercises and it basically involves determining the depth at different points with the assistance of still boats. Before the actual process of sounding, certain initial steps are also involved in supplementing the whole process.


Hydrographic reconnaissance is a basic activity and is performed to determine the depth of the seabed, the location of coral reefs, determining the type and attributes of the bottom. The activity helps in finding the best area as well as the perfect way to conduct the survey for and efficient and cost effective process. Reconnaissance of the survey area supports the project substantially and leads to its completion in accordance with the set standards and safety requirements.

Horizontal controls –

Establishing horizontal control is essential for locating effectively all the features that are associated with the land and water. The control is created with the help of series of lines with the help of theodolite and azimuths via triangulation method. When establishing horizontal survey, there are minimum rules that are followed as they get affected by factors like topography and vegetation.

Vertical controls –

Establishing vertical controls is highly advisable before initializing with the process of sounding surveying. Such controls are based on certain standards that are created along the line of the shore with the help of an instrument called spirit levelling. The benchmarks are utilised for setting tide gages upon which the process of sounding is settled.

Sounding –

Sounding is used for the purpose of determining or evaluating the depth below the surface of the water. Sounding requires certain specifications such as preparation of navigation charts, materials that are required to be dredged as well as sea well backwaters are also required to be designed. Instruments for measuring angles, shore signals and buoys are some basic requirements that are needed for effectively carrying out the activity of sounding.

In addition to providing the facility of conducting hydrographical surveys, we are also regarded as a reliable Soil Testing Company Kolkata and provide concerned services in best quality.