Marine and coastal drone survey.
Joined to bathymetric survey for the tidal environment.
Survey and inspection of coastal and port infrastructure in demanding tidal and maritime environments. Seawalls, jetties, harbour walls, coastal defences and foreshore assets — captured by aerial survey, LiDAR and UAV inspection to deliver the condition record, change analysis and dimensional data needed for coastal asset management.
What does a marine and coastal drone survey cover?
A marine and coastal drone survey records everything above the waterline at the land-sea boundary: cliff faces and foreshore, seawalls, revetments, harbour walls, quay edges, jetties and port buildings. Capture is by UAV photogrammetry and LiDAR inside a tidal working window, referenced to OSGB36 and ODN, and delivered as orthomosaic, digital surface model, condition record and 3D model. Where bed levels below the waterline are also needed, the aerial data is combined with a bathymetric survey on the same datum.
Aerial survey over coastal sections, estuaries and port environments delivers the high-resolution ortho-imagery and digital surface models needed for coastal change detection, foreshore volume analysis and shoreline monitoring. Repeat capture programmes establish the datum-referenced baseline from which accretion, erosion and sediment transport can be quantified — giving coastal engineers and local authorities the spatial intelligence to manage assets and plan intervention. Our Kirk Michael coastal erosion monitoring programme ran five photogrammetric epochs over 1,230 m of eroding cliff frontage between 2019 and 2022, each flown to the same 10 mm GSD design on a re-validated control network with independent GNSS ground truthing.
UAV and ground-based camera rig inspection of harbour walls, jetties, quay edges, sea defences and coastal structures provides the close-range condition record required for maintenance, repair and statutory reporting. Tidal window planning ensures safe access to foreshore and intertidal structures, with inspection operations delivered to the programme constraints of port and harbour operators and coastal flood risk management authorities.
LiDAR scanning of tidal infrastructure delivers the precise dimensional survey of seawalls, revetments, breakwaters and jetty structures that traditional survey methods struggle to achieve in the intertidal zone. Point clouds captured at low water provide accurate surface geometry for design, as-built verification and volume calculations — referenced to AOD and suitable for integration with coastal modelling software and tidal prediction frameworks. Our Dover Cruise Terminal reality model shows a port asset captured as a browser-based 3D model.
Where does a bathymetric survey fit with aerial capture?
A bathymetric survey measures the bed below the waterline by echo sounder from a survey vessel; an aerial survey measures the land, structures and foreshore above it. Airborne LiDAR is absorbed at the water surface and cannot see the bed, and an echo sounder cannot reach the foreshore — so harbour, estuary, reservoir and coastal defence projects that need a continuous surface combine the two, joined in the intertidal zone at low water on a single OSGB36 / ODN datum.
What we capture
Cliff, foreshore, seawall, revetment, quay, jetty and port structure geometry by UAV photogrammetry and LiDAR, specified against the band table in RICS Measured surveys of land, buildings and utilities, 3rd edition (RICS, 2014).
Where the join is made
At low water, with the aerial capture flown to the bottom of the tide and the sounded data brought to the same vertical datum, so the merged surface carries one stated accuracy rather than two unreconciled models.
What it is used for
Dredge volumes and sediment budgets, scour assessment at quay and bridge piers, reservoir and lagoon storage capacity, coastal flood modelling inputs and foreshore change analysis between epochs.
Background reading: what a bathymetric survey is and why it matters, and UAV LiDAR for reservoir surveys, which explains why the water surface is where LiDAR stops.
What sets the scope of a bathymetric survey?
Four things set the scope of a bathymetric survey: the area of bed to be sounded, the depth band and water clarity across it, how the sounder reaches the water (crewed survey vessel or a small unmanned surface vessel for shallow, confined or hazardous water), and the deliverable the design or consent team needs. We define those four at briefing, alongside the aerial scope above the waterline, so the two workstreams are specified once, on one datum, and the merged surface carries a single stated accuracy.
Area and extent
The sounded area is drawn to the same boundary as the aerial capture, with an overlap through the intertidal zone so the two surfaces can be reconciled at low water rather than butted together.
Depth band and conditions
Shallow lagoons, reservoir margins and silted harbours behave differently from open estuary channels. The depth range, turbidity and tidal range decide the sounding method, the line spacing and the tidal correction applied.
Vessel or USV access
Open water is sounded from a crewed survey vessel; shallow, confined or hazardous water from a small unmanned surface vessel launched from the shore. Access and launch points are confirmed at the site visit with the UAV take-off and control positions.
Deliverable
A bed-level digital terrain model, contours and cross-sections on OSGB36 / ODN, merged with the aerial surface where the brief needs one continuous model, and issued with an accuracy statement against the band agreed at briefing.
Coastal and marine survey questions.
What is a bathymetric survey, and how does it fit with an aerial coastal survey?
How is coastal erosion measured by drone?
Can seawalls and jetties be inspected without scaffold or rope access?
How do you work around tides?
What sets the scope of a bathymetric survey?
What accuracy can be achieved in the intertidal zone?
Bring engineering precision to your next project.
Most scoping responses sent within one business day.
RICS-regulated work, led by Philip M. Angell MRICS.