Underwater exploration is commonly required for the structures which are constructed in/under water. The foundations of the structures like bridge piers, pipelines, port structures, and oil well platforms have to be constructed with great caution considering every bit of information as they remain exposed to water all the time. A proper underwater exploration helps in studying the condition of the soil and gaining other useful information required for the construction of sound structures.
Underwater sampling is not entirely different from dry sampling, but it requires special skill and proper equipment in order to obtain a high-quality soil sample. Sampling equipment is commonly installed on barges which are pulled to the construction site, anchored adequately, and castings are installed to a depth of around 2m.
Different tools and equipment are used based on the depth of water and waves. For instance, barge-mounted bridge rig is used for drilling in rivers and lake beds, drillship is used in deep water possibly greater than 1000m, and the platform may be constructed in very deep waters.