JF Subtech provides extensive solutions for nearshore marine and civils projects.

With a significant track record delivering major projects in Africa and Europe, JF Subtech has a substantial asset base operated by experienced crews and engineers. 

We rely on innovative engineering and experience to design and construct fit-for-purpose solutions. Our engineering, project and inspection, repair and maintenance (IRM) teams work closely throughout the project lifecycle, maximising efficiency and delivering optimal time and cost outcomes for our customers. 

Marine construction project lifecycle support

Marine construction

JF Subtech offers a comprehensive range of services to support the full civils project lifecycle.


JF Subtech has established a strong hydrographic survey capability, including: 

  • High-resolution multibeam surveys 
  • Single-beam bathymetry 
  • Side-scan imaging 
  • Sub-bottom profiling 
  • Magnetometer surveys

Supplementary oceanographic and environmental measurement services available include provision of water-level gauges, current meters, CTD and SVP probes.


JF Subtech delivers dredging services primarily focused on nearshore projects including marinas, waterways and port entrances for both new and existing facilities.

With an in-house asset base together with highly experienced construction professionals, we ensure work scopes are executed safely, risk is mitigated, and projects are completed as cost-effectively and efficiently as possible.


With in-house resources, we enable rapid mobilisation of experienced teams to suit project requirements, using regional establishments and operational bases to deliver complex installations at short notice.  

The engineering led EPC and turnkey solutions reduces project risk by providing a complete engineering, procurement and construction solution. We engineer to construct and construct to operate, thereby optimising safety, productivity and cost across every phase of a project.  

Our skilled team offers a full range of nearshore marine construction services, including: 

  • Marine piling support 
  • Scour protection 
  • Confined dredging and capital dredging support 
  • Underwater demolition 
  • Underwater concreting 
  • Preparation of caisson beds and caisson placement 
  • Desalination pipeline solutions from pilot to full scale production plants


JF Subtech provides innovative engineering solutions and delivers inshore and inland underwater projects utilising its professional capabilities and world-class equipment.

Underwater and topside inspection

  • Port, harbour and estuary infrastructure inspections 
  • Bridge inspections 
  • Wier inspections – aerial and below surface 
  • Underwater targeted and condition surveys such as locks, jetties, port infrastructure and bridges 
  • Ships husbandry Underwater Weld Inspection In Lieu of Dry Dock (UWILD)

Repair and maintenance

  • Wet welding 
  • Cathodic protection and anode installation 
  • Removal and installation of lock gates 
  • Silt / sediment removal 
  • Ultra-thermic burning / cutting 
  • Debris clearance

Civils diving

  • General commercial diving services: underwater inspection, maintenance and repair 
  • Diving and marine works for nuclear sites, power stations, water companies and wider industry

Specialist access

  • Confined space access and operations, combined with rope access and diving if required 
  • Rope access works including working at height and accessing underground structures (e.g. reservoirs)
James Fisher is a global supplier of trusted engineering services across the industries we serve, with an unrivalled ability to develop innovative solutions that meet the constantly developing needs of our customers operating in challenging environments.
Want to learn more about our civils capabilities?
James Fisher Subtech
Registered office: Kirkley Business Park, Maconochie Way, Horn Hill, Lowestoft, Suffolk, NR33 0PX, United Kingdom Registered in England No. 103667© 2023 James Fisher and Sons plc