James Fisher’s HydroDigger in action

Fisher Offshore’s advanced underwater excavation system demonstrates its highly flexible capabilities across a range of projects.

The HydroDigger is an advanced form of contactless subsea excavation equipment that can be deployed over a vessel's side and operated remotely and safely from the deck using its integrated launch and recovery system.

It operates by delivering a precisely controlled column of water onto the seabed, fragmenting the surface and displacing soil, sediments, rocks and other surface materials.

"It provides a complete package that’s appropriate for a wide range of functions, from excavations for new pipeline systems, for example, through to the decommissioning and burial of life-expired installations in accordance with regulatory requirements,’ says Steve Gray, project manager, at Fisher Offshore.


The work scope was to recover a 40 metre length of damaged flexible flowline which was buried under 1 metre of drill mud in the Osprey Field, North Sea. The HydroDigger was used to dredge the drill mud off the flowline to expose it for disconnection.


Integrated Subsea Services

Services provided:

  • Subsea excavation
  • Control system
  • Real-time sonar monitoring

Benefits delivered:

  • Simple and rapid deployment
  • Highly flexible capabilities across a range of projects
  • On-budget and on-time


Download the Mass flow excavation: James Fisher's HydroDigger in action case study.