Diver-Deployed NDT Inspection

Ensuring the integrity of underwater assets

TSC Subsea’s underwater inspection services provide an extensive array of ROV and diver-deployed inspection solutions featuring advanced NDT methods.

We offer diver-deployed robotic and manual scanners to suit various underwater inspection challenges on assets such as pipelines, subsea storage tanks, offshore structures, and marine vessels.

Diver Underwater Inspection

With over a decade of experience tackling subsea inspection challenges across a range of water depths, from the splash zone to ultra-deepwater, we have the expertise to assess all common damage mechanisms linked to critical subsea assets.

Inspection Capabilities:

  • Validation of In-Line Inspection (ILI) surveys.
  • Evaluation of pipeline corrosion and erosion.
  • Weld inspection of subsea structures.
  • Crack detection and sizing in lieu of MPI.
  • Through coating wall thickness measurements.
  • Flange face corrosion inspection.
  • Flooded Member Detection (FMD).
  • Hull surveys, propellers and bilge keel welds.
Diver PEC undereater Inspection

Pulsed Eddy Current inspection of PLEM

VISTA diver underwater weld inspection

VISTA diver-assisted scanner conduction PAUT underwater weld inspection


  • Pipelines
  • Underwater Structures
  • FPSOs and Vessels
  • Splash Zone
  • Manifold Piping
  • Jumpers
  • Jackets / Pontoons
  • Caissons
  • Storage tanks

Advanced Diver NDT Methods

Alternating Current Field Measurement (ACFM):

  • Surface-breaking crack detection and sizing.
  • Recognised and approved by many certification bodies, including DNV, ABS, BV and Lloyds.
  • Computerised auditable data, unlike MPI.
  • Reliable results despite surface imperfections.
ACFM Data showing crack in weld

ACFM data with crack detection and sizing.

Acoustic Resonance Technology (ART):

  • Through coating wall thickness measurements.
  • Exclusive to TSC Subsea.
  • Inspect through thick subsea coatings and materials with high attenuation >100 mm (4 in).
  • Highly accurate depth sizing of +/- 0.2 mm.
ART data with underwater pipeline corrosion

ART data detailing wall thickness measurments.

Subsea Phased Array (SPA™)

  • High-resolution corrosion mapping and volumetric weld assessment.
  • Advanced techniques, including ToFD and TFM.
  • Improved defect detection with a high probability of detection from a single probe position.
  • Suitable for ferrous and non-ferrous assets.
Underwater PAUT data

SPA corrosion mapping data detailing pitting.

Subsea Pulsed Eddy Current Testing Array (SPECTA™)

  • Semi-quantitative screening method.
  • Wall thickness measurements through coatings such as concrete.
  • Substantial cost savings by eliminating coating removal.
  • Scan in ‘screening mode’ for greater efficiency.
Underwater PEC data

SPECTA data corrosion detection during ILI verification on CWC.

Not sure what NDT technology is best suited to your subsea inspection application?

Diver Deployed NDT Scanners and Probes

Regardless of the deployment method, TSC Subsea’s array of advanced NDT solutions enhances data quality and delivers live, fully auditable, and repeatable inspection results.

VISTA Underwater NDT Scanner

VISTA – Versatile Inspection System for Subsea Technical Assessments

  • Multifunctional hybrid Advanced Ultrasonic (AUT) and ACFM scanner, optimised for diver deployment.
  • Capable of high-resolution corrosion mapping and weld inspection.
  • Suitable for both circumferential and longitudinal scanning of pipelines ranging from 100mm (4 in) to flat plates.
ACFM propeller inspection

Diver-assisted handheld scanners and probes

  • Versatile range of multi-technology tools suitable for all scenarios..
  • Flexibility to navigate complex underwater environments..
  • Effective for quick deployment in emergency situations.
vCompact diver deployed inspection


  • Inspect tight access field joints and narrow tubular structures.
  • Versatile design for axial and circumferential measurements.
  • Low-profile for tight access applications.

Case Studies

Through Coating Wall Thickness Inspection for ILI Verification

Beach Energy Ltd contracted TSC Subsea to carry out a wall thickness inspection through coating on the 20 in pipeline. The inspection was to determine the size and depth of corrosion which had been identified during a previous In-Line Inspection (ILI).

4” of Coating no Match for ART and ARTEMIS

The purpose of the inspection was to measure effective steel thickness through 4 inches of pipeline insulations made of Glass syntactic polypropylene and injection moulded polypropylene. Scanning operations were carried out at 2000 meters water depth.

Inspecting Concrete Weighed Pipes with SPECTA

TSC Subsea was contracted by a client to carry out wall thickness assessment of Condensate Export Pipeline (CEP) and Pipeline End Manifold (PLEM) without removing the protective concrete weight coat (CWC).

See all case studies

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Our services

Subsea Structures

Splash Zone

Vessels and FPSOs

Flexible Risers