IHO-Compliant Hydrographic Surveys

Drone Sonar Surveys.

Aerial-deployed tethered sonar buoys and USV (uncrewed surface vessel) integration for harbour, lake, and reservoir bathymetry beyond the reach of green-laser LiDAR.

“Every drone pilot on this network is personally vetted by me — insurance, qualifications, flight history.”

Peter Leslie · Founder & GVC Drone Pilot

Trusted by site managers & agencies across the UK

Need a water body surveyed?

Post your details to compare quotes from sonar/USV specialists.

Deep or access-restricted water needs more than a drone camera.

Dam engineers, harbourmasters, and reservoir owners need bed data where LiDAR gives up and manned boats cost a fortune to mobilise.

Deep Water Defeats LiDAR

Green-laser bathymetric LiDAR tops out around 3 m depth in clear water, and far less in turbid UK reservoirs. For reservoirs over 10 m deep or silt-laden lakes, only acoustic survey delivers reliable bed geometry.

Manned Vessels Are Slow

Mobilising a crewed survey boat with skipper, surveyor, and heave-compensated MBES costs £4k–£10k per day with weather-window stand-downs. A USV runs autonomous transects at a fraction of that cost, unmanned and on-schedule.

Restricted Access Sites

Water utility reservoirs, tailings ponds, and MOD waters often ban manned craft for biosecurity, contamination, or security reasons. A decontaminated USV deployed from shore avoids the problem entirely.

Sonar is acoustic physics, not a GoPro under a raft.

By Peter Leslie, Founder & GVC Drone Pilot

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Single-beam (200 kHz) echosounders suit reconnaissance work and deep reservoirs; multi-beam (240–400 kHz) delivers the sub-metre coverage dredge contractors and dam engineers actually need. Getting the wrong tool wastes the whole mobilisation.

Real USV work requires sound-velocity profiling at the start of each day, RTK-driven heave-and-tide correction, IMU alignment calibration, and patch-test validation. Without those, the data fails an IHO S-44 audit.

Every sonar survey on this network is flown and sailed by drone operators running proper USV hardware (SeaRobotics, Apache 3, or equivalent) with hydrographic surveyors processing the data, not drone hobbyists.

IHO-Compliant Drone operators

USV & Multi-Beam Specialists

Hydrographic outputs, engineered for asset decisions.

Our network operators deliver IHO Order 1a sonar data ready for reservoir engineers, dredge contractors, and dam safety reviews.

Bathymetric Charts

Single-beam or multi-beam chart of the bed, referenced to OSGM15 and tidal datum, delivered as GeoTIFF, XYZ, or CAD surface ready for direct ingest into engineering workflows.

Reservoir Volumetrics

Storage curves, sedimentation deltas between survey epochs, and dredge-volume calculations — essential for Reservoirs Act inspections, siltation monitoring, and water-supply planning.

CAD-Ready Contours

Contoured bed surfaces at client-specified intervals, exported as DWG/DXF for direct overlay onto dredge plans, harbour layouts, or dam downstream-zone mapping.

Book your sonar survey in 3 steps.

We route your brief to USV and tethered-sonar specialists in your region.

Describe the Water Body

Tell us the site, depth range, area, access constraints (biosecurity, security, vessel bans), and the asset decision you need to support.

Compare Hydrographic Teams

We route your brief to drone operators running proper USV platforms with single or multi-beam payloads. Receive competitive quotes with IHO order, deliverables and turnaround.

Survey & Process

Your drone operator handles permissions, SVP, patch tests, and transect plans, then delivers charts, volumes, and CAD overlays via secure cloud link.

Start Your Project Brief

Trusted across reservoirs, harbours, and dams.

See how water utilities, harbourmasters, and dam safety engineers use USV sonar through our network.

"Biosecurity rules meant no external boats on the reservoir. The USV team turned up with a decontaminated platform, surveyed the full 80 ha in two days and delivered a storage curve that satisfied our Reservoirs Act inspecting engineer."

Iain Paterson

Reservoir Asset Engineer, Scottish Water, Stirling

"We needed a pre-dredge MBES survey of the inner harbour inside a tight tidal window. The team matched the schedule, delivered IHO Order 1a data, and the dredge contractor priced straight from the CAD surface."

Chloe Harrington

Harbourmaster, Lowestoft

"For a dam safety review we needed siltation deltas against the 2012 baseline. The USV multi-beam survey returned centimetric bed geometry that dropped straight into our downstream-zone modelling."

Dr Omar Farooq

Dam Safety Engineer, Cardiff

Sonar & USV Survey FAQ

Technical answers on beam selection, compliance, and hybrid surveys.

When do I need multi-beam over single-beam?

Single-beam (200 kHz) is fine for reconnaissance, storage-curve reservoir work, and low-resolution volumetrics. Multi-beam (240–400 kHz) is required where sub-metre bed geometry matters — dredge volume tenders, harbour as-builts, dam toe inspections, and pipeline burial assessments.

How does USV compare to a manned-vessel survey?

On data quality, a well-calibrated USV with a modern MBES and INS is indistinguishable from a crewed survey vessel. On cost, it is typically 40–70% cheaper, with faster mobilisation, shallower access, and zero personnel exposure. The trade-off is transit distance — for large offshore surveys manned vessels still win.

Is the output IHO S-44 compliant?

Yes. Network operators deliver IHO S-44 Order 1a as standard — full feature detection, defined TVU and THU, and documented uncertainty. Higher orders (Exclusive, Special) are available where the asset risk justifies them. Reports include patch-test and SVP logs for audit.

Can you combine with drone LiDAR for shore-to-deep coverage?

Yes — hybrid surveys are the cleanest answer for most UK reservoirs and estuarine sites. Green-laser drone LiDAR covers the intertidal and shallows, USV sonar picks up from roughly 2 m onwards, and the two datasets are merged into a single seamless DEM referenced to a common datum.