Over the past weeks, our team ventured into Singapore’s waters to undertake a detailed marine survey to map potential submarine cable routes. Our scope included two major technical workstreams:

Bathymetric Survey – Mapping the Seafloor

Using multibeam echo sounders and advanced hydrographic equipment, we created high-resolution 3D models of the seabed as identifying seabed depth variations, contours, and slopes is critical to cable route planning.

Bathymetry helps avoid underwater hazards like shipwrecks, pipelines, rock outcrops, and steep seabed gradients, ensuring safe and efficient cable installation. It also enables us to model hydrodynamic forces (currents, tides) that could impact cable stability over the long term. This step lays the foundational layer for technical design, environmental impact assessment, and construction planning.

Geotechnical Investigation – Understanding the Subsurface

We conducted seabed sampling (via core sampling, grab samples) and in-situ tests (such as cone penetration tests, or CPTs) along the proposed cable corridor. Determining the soil composition (e.g., clay, sand, silt, rock) helps assess the seabed’s suitability for cable burial.

We evaluate key parameters like shear strength, density, and sediment layering — all of which influence how easily cables can be buried, protected, and maintained. Understanding geotechnical conditions allows for tailored burial depth design, choice of protection methods (e.g., trenching, rock dumping), and minimisation of installation risks and without this investigation, cables could be improperly buried, exposed to environmental risks, or damaged during operation.

Regulatory Engagement – Navigating New Waters

Given the novelty of such projects in Singapore, securing marine survey approvals required proactive collaboration with multiple government agencies. We worked closely with regulators to align on technical standards, environmental protection measures, and maritime safety requirements, setting important precedents for future projects.

With the successful completion of the marine survey, SJ demonstrated our capability to lead and support pioneering renewable energy infrastructure in complex marine environments. This milestone not only advances Singapore’s cross-border energy goals but also showcases SJ’s strengths in delivering technical excellence, regulatory navigation, and project execution for first-of-their-kind projects.

To find out more about the process of planning subsea cable routes, using the Tanjung Pinggir (Batam) to Jurong Island (Singapore) project as a case study to highlight the key steps, download our thought leadership paper below. The paper covers the role of initial desktop studies guided by ICPC recommendations, comprehensive marine surveys (geophysical and geotechnical), stakeholder engagement, and regulatory compliance, whilst emphasising the importance of identifying hazards, mitigating risks, and ensuring environmental protection throughout the planning stages to enable efficient and sustainable cross-border energy solutions.