Based in the hot shipping spot of Marseille, Subsea Tech is perfectly located to deal with the shipping companies and understand their concerns in terms of asset maintenance. Commercial ships for cargo or cruise require regluar maintenance, generally required by law, especially for their underwater parts (hull, thrusters, ballast). Preliminary inspections are required prior to ship maintenance but carrying out these inspections in dry-dock is a costly and time-consuming operation.  Moreover, ballast inspections generally require emptying them in a first time and deploying rope access work teams. These operations generate high risk, cost and environmental constraints.

Aware of these constraints, Subsea Tech proposes a range of solutions for UWILD (Underwater Inspection In Lieu of Dry-Dock) applications. Our mini-ROVs carry out underwater inspections and measurements, thus enhancing the global maintenance schedule and reducing drastically the cost and duration of ship maintenance operations.

Ship hulls and thrusters inspection

Subsea Tech’s mini-ROVs realize visual and sonar inspections as well as NDT operations directly in water on ship hulls and thrusters (UWILD). An experienced operator can complete a vessel inspection in a few hours only, thus reducing the inspection cost and duration compared to a diver team and improving the maintenance schedule.


  • Visual detection of defects using mini-ROV and sonar
  • Defect scaling using laser pointer system mounted on ROV
  • Ship hulls thickness measurement using US gauge mounted on mini-ROV
  • Anode cathodic protection measurement using CP probes mounted on mini-ROV


  • Reducing cost and duration of inspections
  • Optimizing maintenance schedule
  • Reducing dry-docking time
  • Reducing human risk related to underwater inspection (no diver)

Ballast inspection

Subsea Tech designed, in the framework of a partnership with Naval Group (DCNS), a bespoke solution to carry out ballast inspection for FPSO and other big ships. ROBIS mini-ROV allows the operator carrying out visual inspections and NDT operations (thickness, CP measurements) in ship ballasts. Thanks to its innovative positioning system, ROBIS provides the operator with its real-time position in the ballast. Its small dimensions allow ROBIS entering a 500mm manhole.


  • Ballast visual inspection using mini-ROV to identify defects and schedule maintenance
  • Thickness measurements using US gauge mounted on mini-ROV
  • Cathodic protection measurement using CP probes mounted on mini-ROV


  • Inspection and measurement mapping inside the ballast to enhance maintenance scheduling
  • Reducing costs and human risk related to ballast inspection
  • Reducing environmental issues related to ballast emptying

Supervision of wreck raising

In the framework of wreck raising operations, Subsea Tech offers to the entrusted operators a range of services and tools to optimize operation scheduling and monitoring. Subsea Tech combines video and acoustic inspection technologies, mounted on divers, mini-ROVs and USVs in order to provide the required information and data to ensure an optimal preparation and monitoring of the operations.


  • Wreck identification and positioning using side scan sonar and multibeam imaging sonar mounted on a boat or a USV
  • Wreck 3D modeling using multibeam echosounder mounted on boat or USV
  • Video inspection of the wreck using mini-ROV or underwater video camera system mounted on a diver
  • Real-time video monitoring of the operations using mini-ROV or underwater video camera system


  • Optimizing recovery operations through a detailed survey of the area and an accurate wreck configuration
  • Reducing costs and risks related to the survey compared to diver operations
  • Real-time video monitoring of the operations

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