Marine UXO Survey Services

UXO Risk Mitigation Services

We specialise in marine UXO surveys designed to locate and map unexploded ordnance (UXO) that could pose a potential risk to construction, dredging, and other seabed activities.

Detailed surveys are used as part of the wider UXO risk mitigation process, helping to detect, locate, and assess potential wartime munitions present on or below the seabed. Even after all this time, UXO risk management is an important step in allowing projects to move ahead safely limiting the threat to people, equipment and the wider marine environment.

Importance of Marine UXO Risk Mitigation Surveys

Many people are surprised to learn that there are still thousands of unexploded bombs, mines, and other munitions littering the seabed from past conflicts. Marine UXO contamination can be extremely dangerous, even decades after they were dropped or fired.

Any disturbance to the seabed during construction or dredging projects has the potential to trigger an explosion or release harmful substances into the marine environment. The potential risk posed by discarded munitiions is not only a threat to workers but also has serious consequences for marine life and ecosystems.

While local and national archives can provide insight into areas affected, for many construction sites, UXO specialists are required to evaluate whether additional UXO hazard sources, such as naval mines or artillery shells, may be present. Typically, if your site is in a moderate or high-risk area, it is strongly recommended that you employ various risk mitigation strategies, including a detailed UXO risk assessment, before any intrusive work goes ahead.

One such strategy is a marine UXO survey. By pinpointing the survey position of potential UXO targets, non-intrusive surveys play a critical role in understanding the potential UXO risk and helping to influence the next steps, from target investigation of ferrous anomalies to UXO clearance activities.

Comprehensive UXO Surveys

We offer a range of UXO survey services in the nearshore environment to help mitigate UXO risk for our clients. Our extensive experience spans the UK and northern Europe, where we have successfully completed numerous projects in challenging environments.

We always aim to survey with minimal disturbance to the seabed, marine life, and other sea users. We tailor the approach to the specific needs of each project for complete coverage and accurate results. With a commitment to safety and accuracy, our clients receive the most reliable survey data possible, allowing them to proceed with their projects confidently.

Coastal Onshore and Intertidal UXO Surveys

Coastal onshore and intertidal UXO surveys present a set of unique challenges due to the distinct nature of these environments. One significant challenge is the constantly changing tidal conditions, which can impact access to survey sites as well as the accuracy of data collection. Tidal fluctuations require precise scheduling to let survey teams work safely and efficiently, often within narrow time windows.

The dynamic nature of coastal and intertidal zones, characterised by frequent sediment movement and erosion, can shift UXO or bury them deeper, complicating detection and mapping efforts. Accessibility issues also come into play, as some coastal regions may be difficult to reach or have restrictions due to environmental protections.

The Latest Technology for Drone UXO Surveys

The traditional G-858 magnetometer is augmented by the latest in UAV technology to enhance UXO detection capabilities in intertidal areas, such as the Sensys R4 Magnetometer.

This ultra-lightweight magnetometer, also known as the MagDrone R4, can be attached to any drone capable of carrying a payload over 2 kg, significantly enhancing our drone UXO surveys.

Nearshore UXO Survey

From strong currents to unpredictable weather, the dynamic nature of shallow coastal waters and various marine environments presents a range of unique challenges for UXO surveys.

Tidal cycles must be meticulously planned to ensure accurate and efficient survey operations, while the shallow water depths restrict the manoeuvrability of survey vessels. The potential presence of active or abandoned underwater infrastructure further complicates these operations, adding another layer of complexity.

Our nearshore UXO surveys typically involve a transverse gradiometer (TVG) frame equipped with two Geometrics G882 magnetometers. In areas where deploying a frame is not possible, we use tightly spaced single magnetometers. Additional sensors like multibeam echosounders, side scan sonar, and sub-bottom profilers provide comprehensive data for accurate mapping and risk assessment.

UXO Surveys in Built-up Areas

Conducting UXO surveys in built-up areas, such as ports or industrial sites, also presents challenges.

Built-up areas often contain significant amounts of ferrous material in buildings, infrastructure, and buried utilities. This abundance of metal creates background "noise" that can mask or interfere with UXO detection signals.

This means that a non-intrusive magnetometer survey may not be the best solution for detecting UXO in these areas, and alternative technology may be necessary. For such projects, in the past we've collaborated with Kraken Robotics to deploy their Sub Bottom Imager (SBI) system.

This sophisticated 3D chirp technology creates high-resolution images of the sub-seabed, allowing accurate target identification. The system can be deployed from vessels or shoreside cranes, with data processed to ensure precise target listings for further investigation.

Offshore UXO Survey

Offshore, larger vessels allow for more extensive deployment capabilities, which means that surveys can be more straightforward and efficient. However, offshore surveys come with their own unique set of challenges.

From maintaining a consistent height above the seabed to maximising coverage of large areas, offshore UXO surveys also require precise planning and tight control.

Our team has experience in using multiple EIVA ScanFish to maximise productivity, leveraging semi-automated flying for efficient surveying. For large-scale, non-ferrous surveys, PanGeo’s custom-built ROTV, SeaKite, offers exceptional performance, acquiring up to 130km of SBI data per day in optimal conditions. The ability to cover such vast areas swiftly and accurately is ideal for large marine projects, where time and precision are of the essence.

Why Choose SEP Hydrographic?

Our team has decades of experience in UXO detection surveys in the marine environment, often surveying under challenging conditions. We have always worked closely with trusted UXO consultants to deliver a quality end-to-end service, and understand the unique challenges faced with these types of marine projects.

Contact us today to learn more about our marine UXO survey services. Our team is here to answer any questions and provide the support you need to move forward with confidence.

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