Site preparation

Trusted by the world’s leading developers and primary contractors, JF Subtech is a supplier of choice for seabed preparation scopes.

Drawing on our flexible, in-house tooling capability, our expert teams offer an extensive range of services, from surveying, route clearance including UXO and boulder clearance, to excavation & trenching.

Operating on a global scale, we use the latest technology to deliver first-class results for any project scope.



We help mitigate risks and plan for any maintenance by providing a suite of hydrographic and shallow geophysical surveys in any water depth.

Using a variety of different survey methods, we determine the status of the seabed and the shallow sub-seabed sediments, and map and investigate any structures or debris.

Our solution covers recording and measuring any problem areas, inspecting points of concern, providing corrective engineered solutions and full reporting.

•Hydrographic survey

•Shallow water geophysical survey

•Vessel positioning services

•Survey data processing

•Survey data interpretation and reporting

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JF Subtech has performed UXO operations including identification, detonation or removal in countries including Finland, Denmark, UK, Estonia and Germany. We follow all local licences permissions, environmental and archaeological mitigation protocols, liaising with maritime traffic coordination and coastguard agencies. Our team provides a wealth of experience and knowledge across the relevant disciplines, constantly monitoring new developments within the industry.

A turnkey UXO solution, from initial survey through to subsequent positive explosive ordnance disposal (EOD) on designated targets, using the latest technologies and techniques to deliver results safely, efficiently, and cost-effectively.

• Detection, identification, removal and disposal

• Innovation in disposal including bubble curtain noise attenuation

• Emergency UXO response - 48hr turnaround (subject to customer’s licence)

• Proactive impact mitigation, fully adhering to environmental requirements.


Boulder clearance

Specialist boulder removal assets provide for safe and fast removal or relocation of boulder obstructions for any project. Utilising specialist grabs and experienced personnel, sites are rapidly cleared as part of enablement works.

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Excavation and trenching

Our fleet of controlled flow excavation (CFE) equipment provides a non-contact form of excavation that eliminates the risks associated with other excavation methods, and is especially suited to the following applications:

  • Pipeline and cable trenching
  • Backfilling
  • De-burial for emergency repair/IRM works
  • Seabed preparation and clearance
  • Pre-sweeping preparation
  • Rock dump dispersal and removal
  • Decommissioning and abandonment work
  • Free-span rectification
  • Harbour and channel clearance

Subsea excavation services:

  • A range of CFE tooling spreads that deliver between 2,000 - 16,000 liters of water per second
  • Patented hard soil jetting capabilities up to 300kPa
  • Shallow water excavations from 1.5m
  • Deep water excavations up to 3,000m
  • Safe on live cables and pipelines
  • Fully controllable output
  • Reduced and flexible deck footprint
  • Accurate and efficient excavation rates, reducing valuable vessel time

Further capabilities