POST-CYCLONE HYDROGRAPHY · WESTERN AUSTRALIA

Dampier Post-Cyclone MBES Survey

A shallow-water infrastructure baseline across six survey areas

Client / end client

Oceanic Offshore / Rio Tinto

Region

Dampier Port, Pilbara, WA

Fieldwork

4–6 May 2026

QOffshore role

Hydrographic survey delivery support

Platform

SCIMITAR + Norbit iWBMS

Processing

Qinsy acquisition + Qimera QA/QC

The client issue

Following Severe Tropical Cyclone Narelle, high-resolution hydrographic data were required across six priority areas in the Dampier Port operational environment. The survey needed to map seabed levels and morphology around seawall toes, shallow margins, jetty approaches and infrastructure-adjacent seabed, identify features relevant to engineering review, and establish a repeatable bathymetric baseline for future comparison.

Survey areas

251.7 million

Accepted soundings

0.25 m

Grid resolution

Chart outputs

The survey challenge

Active-port execution

Survey lines had to be coordinated around vessel movements, marine infrastructure and restricted access while maintaining safe operations.

Shallow, structure-adjacent access

Seawalls, jetty piles, shallow margins and causeway edges demanded manoeuvrable vessel handling and targeted infill where safe and practicable.

Controlled vertical referencing

Tide, barometric pressure, sound velocity, GNSS and motion data had to be integrated consistently to reduce final surfaces to Chart Datum.

Survey delivery

The three-day field programme used the Oceanic Offshore vessel SCIMITAR with a pole-mounted Norbit iWBMS multibeam system. Qinsy supported acquisition and field quality control, while Qimera was used for processing, validation and final surface generation. Survey control combined GNSS, motion and heading data, measured offsets, in-water roll calibration, sound-velocity profiles, local tide observations and barometric correction. Final products were referenced to GDA2020 / MGA Zone 50 and reduced to Chart Datum.

Outcome and client value

Full multibeam coverage was achieved across the six nominated areas within the active-port constraints. The processed surfaces documented seawall and rock-armour relief, jetty piles and supports, tyre-like and block-like objects, an approximately 8.5 m linear feature, and localised sediment accumulation near jetty infrastructure. The dataset provides a controlled hydrographic baseline for engineering review, asset-management interpretation and future change detection. Structural or asset-integrity conclusions remain subject to qualified engineering assessment.

Survey deliverables

0.25 m gridded bathymetric surfaces and processed XYZ point data
Contour, spot-depth and shaded-relief charts across the six survey areas
GDA2020 / MGA Zone 50 products reduced to Chart Datum
GIS package including contour layers and GeoPackage-compatible outputs
Feature / anomaly register supporting targeted engineering and asset review

Survey chart

Why it mattered

A controlled three-day MBES campaign converted post-cyclone uncertainty across six active-port locations into a traceable bathymetric baseline. The survey gave the project team a single depth and morphology dataset for prioritising follow-up inspection, reviewing seabed and infrastructure-adjacent conditions, and measuring future change.

Explore our hydrographic survey services for port seabed mapping and repeatable baselines to support engineering review.