Leask Marine’s nearshore surveying focuses on collecting detailed seabed and water column data in shallow coastal areas where offshore infrastructure approaches land.
It ensures that installation operations are safe, efficient, and compliant with regulatory standards.
For our nearshore infrastructure projects, this typically involves understanding seabed topography (bathymetry) and sediment type, together with identifying obstacles or hazards (rocks, debris, pipelines, utilities). We also use it for supporting precise positioning for equipment and cable alignment, and providing data for design and construction planning, including cable burial and protection methods.
Why Nearshore Surveying is Critical
- Safety: Avoids hazards for personnel and equipment.
- Efficiency: Reduces delays by identifying and mitigating issues before installation.
- Compliance: Meets regulatory requirements for environmental protection and navigational safety.
- Longevity: Ensures cable and infrastructure are stability, minimising maintenance.
Landfall HDD
The survey role during the Landfall HDD would be to map the seabed at the nearshore entry / exit points to identify hazards and optimal drill exit location. It can characterise the sediments to ensure drill can penetrate without obstruction, and also detect utilities, pipelines, or obstacles that could interfere with drilling operations.
PLGR
The survey Role during the PLGR is generally to map the route of the grapnel train and verifying the route has been covered and cleared.
Pull-In Operations
The survey Role can verify the pull-in route is clear and within tolerance for cable bending radius, and confirm bathymetry supports safe vessel positioning and equipment operation. It also can monitor for soft sediments or exposed obstacles that could impede pull-in
Cable Protection
The survey Role can identify seabed areas requiring protection (rocks, mattresses, or concrete), model cable stability under currents and wave action, and confirm suitability for trenching, burial, or armouring.
Mattress & Rock Bag Installation
The survey Role can determine exact location, dimensions, and seabed slope for mattress or rock placement identify areas with soft sediments versus hard substrates to ensure stability, and verify installed protection after deployment for conformance.
Survey Techniques Typically Used by Leask Marine
Leask Marine provides comprehensive nearshore survey services to support critical infrastructure operations, including Landfall HDD, PLGR, pull-in operations, cable protection, and mattress and rock bag installation. The company employs the full suite of industry-leading survey techniques, including multibeam echo sounders (MBES), side scan sonar (SSS), sub-bottom profiling, ROV and diver inspections, geotechnical sampling, and precise positioning.
By integrating these techniques, Leask Marine delivers high-resolution seabed mapping, obstacle detection, sediment characterization, and real-time monitoring, ensuring accurate data acquisition and operational assurance. This holistic approach enables safe, efficient, and reliable project execution in the challenging nearshore environment.
- Multibeam Echo Sounders (MBES): High-resolution seabed mapping.
- Side Scan Sonar (SSS): Detects obstacles, debris, and seabed features.
- Sub-Bottom Profilers: Determines sediment layers for HDD, burial, and stability.
- Diver /ROV / Camera Inspections: Visual confirmation of seabed conditions, cable, or protection works.
- Geotechnical Sampling: Boreholes or cone penetration tests to characterize sediments.