Underwater Survey Methods Compared: Sonar, ROV, and Diver Survey
Not every underwater survey is the same job. Measuring reservoir depth for capacity estimation is completely different from inspecting a submerged pipeline joint for corrosion. Three main methods handle this work, and choosing the wrong one wastes both time and budget.
Single Beam Echo Sounder (SBES)
A sonar transducer mounted on a survey boat measures depth in a straight line beneath the vessel. Combined with DGPS positioning, this produces a grid of depth measurements across the entire water body. It is the standard method for bathymetric mapping of reservoirs, canals, rivers, and lakes.
Move your mouse to see how sonar depth pings light up differently based on the underlying bed profile
Method Comparison
| Method | Best for | Depth range | Speed |
|---|---|---|---|
| SBES Sonar | Reservoir capacity, silt volume, canal bed mapping | 0.5m - 200m | Fast, 10 km/day |
| ROV Inspection | Structural inspection, pipeline, dam wall assessment | Any depth, no diver risk | Slower, detailed |
| Diver Survey | Physical sampling, close-up manual inspection | Limited by diver safety depth | Slowest, highest risk |
Choosing the Right Method for Your Project
For most Indian irrigation, reservoir, and port projects, sonar-based bathymetric survey covers the vast majority of requirements at the lowest cost and fastest turnaround. Learn more about our hydrographic and bathymetric survey services.
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