Subsea cable installation is how offshore cables, for wind farms, interconnectors and telecoms, are laid along the seabed and then protected by burial. It involves three closely linked operations: cable lay (installing the cable along a surveyed route from a specialist vessel), ploughing (laying and burying in a single pass), and trenching (cutting a trench to bury the cable, often after it is laid). Together they get cables safely from A to B and protect them for decades. Each is delivered by specialist offshore crews.
The offshore world runs on cables. Wind farms send their power ashore through them, countries trade electricity across them, and most of the world’s data travels beneath the sea inside them. Getting those cables safely onto and into the seabed is a precise, high-value engineering discipline known as subsea cable installation. This guide gives an overview of how it works and links to detailed explainers on each main method, so whether you are planning a project or building a team, you can see the whole picture and dive into the detail.
What is subsea cable installation?
Subsea cable installation is the full process of getting an offshore cable from a vessel onto, and usually into, the seabed along a planned route. It spans route survey and seabed preparation, laying the cable accurately under controlled tension, burying it to protect it, and the shore landings and tie-ins that connect it to onshore grids and offshore structures. The work supports offshore wind inter-array and export cables, cross-border interconnectors, and the telecoms cables that carry global data. Because a cable failure is costly and disruptive, installation is engineered to get the cable both accurately positioned and well protected.
What are the main methods?
Three closely related operations sit at the heart of subsea cable installation. They are often combined on a single project:
- Cable lay. Installing the cable along the seabed from a specialist cable-lay vessel, under controlled tension and often using dynamic positioning to stay precisely on route. Read more in our subsea cable lay guide.
- Laying and burying the cable in a single pass, with a plough towed behind the vessel cutting a trench and the seabed backfilling over the cable. The most economical burial method for long runs where conditions allow. Read more in our cable ploughing guide.
- Cutting a trench to bury the cable, by mechanical cutting, jetting or mass-flow excavation, often as post-lay burial after the cable is on the seabed. Read more in our subsea trenching guide.
In practice, the right combination depends on the cable type, the route and the seabed. A long export cable might be laid and ploughed in one operation, while inter-array cables between turbines are commonly surface-laid and then trenched.
Why is burial so important?
Laying a cable accurately is only half the job; protecting it is the other half. On an exposed seabed, cables are vulnerable to anchors, fishing gear, currents, seabed movement and impact, and a single fault can take weeks and substantial cost to find and repair, while interrupting power or data. Burying the cable, typically one to three metres beneath the seabed, dramatically reduces these risks and is central to the long-term reliability of offshore infrastructure. That is why ploughing and trenching are integral to installation rather than optional extras.
What does a subsea cable installation project involve?
A typical campaign moves through several stages: surveying and clearing the route of boulders and obstructions, mobilising the vessel and equipment, laying the cable to the seabed under controlled tension, burying it by ploughing or trenching, completing shore landings and tie-ins to turbines or substations, and verifying burial depth and protection on completion. Each stage demands specialist expertise, vessels and equipment, and tight coordination, often in challenging weather and sea conditions.
What roles deliver subsea cable installation?
These projects are delivered by specialist offshore teams whose skills are in high demand as offshore wind and global connectivity expand. Typical roles include cable-lay and cable engineers, trenching and burial engineers, ROV pilots and technicians, dynamic positioning operators, survey engineers and surveyors, jointers and termination specialists, offshore and project engineers, marine and vessel crew, and offshore managers and client representatives. These are technical, often rotational offshore roles requiring specific certifications, the kind of niche talent a sector-specialist recruiter is best placed to source.
How WRS supports subsea cable installation recruitment
Offshore, subsea and renewables work is core territory for WRS. We recruit the specialist talent that cable lay, ploughing and trenching campaigns depend on, across offshore and maritime, subsea, offshore wind and the wider renewable energy sector. Our recruitment solutions and contractor services cover permanent and contract hiring, mobilisation and compliant payroll, so you can crew installation projects worldwide.
If you are staffing a subsea cable installation project, get in touch to discuss your requirements, or submit your CV if you work in subsea and offshore.
FAQs
What is subsea cable installation?
The full process of laying an offshore cable along the seabed and burying it to protect it, covering route survey, cable lay, ploughing or trenching, and shore landings and tie-ins. It supports offshore wind, interconnectors and telecoms cables.
What is the difference between cable lay, ploughing and trenching?
Cable lay is installing the cable along the seabed. Ploughing lays and buries it in a single pass. Trenching cuts a trench to bury the cable, often after it is laid. See our detailed guides to cable lay, ploughing and trenching.
How deep are subsea cables buried?
Typically one to three metres below the seabed, depending on the hazards present and the ground conditions. Burial protects the cable from anchors, fishing gear, currents and impact, greatly improving long-term reliability.
Why is subsea cable installation in such demand?
Because offshore wind is expanding rapidly and global data and power connectivity keep growing, all of which require thousands of kilometres of new subsea cable to be installed and protected, driving strong demand for specialist offshore talent.
How can WRS help with subsea cable installation projects?
WRS recruits the full range of specialist offshore and subsea talent these projects need, from cable-lay, trenching and ROV engineers to DP operators, survey and marine crew, across more than 90 countries. Visit worldwide-rs.com or contact us to discuss your project.
