A compact, field‑ready reference for inspection divers preparing for Underwater NDT Inspection Diver exams. Use alongside your company SOPs and project specifications.
✓ = core; • = awareness/overlap
Asset terminology & feature IDs (pipeline/risers/trees/manifolds) ✓
Visual inspection: GVI/CVI, cleaning standards, measurement & sketching ✓
Photography/video with overlay & commentary ✓
CP survey (Ag/AgCl/seawater), interpretation & troubleshooting ✓
UDTM (thickness) — setup, calibration, limits ✓
ID & %‑cover Marine growth methods (SACFOR, quadrats, line‑intercept) ✓
Fluorescent/visible MPI (field fundamentals) •
Toe‑grinding (method, acceptance, re‑inspection) •
Advanced UT (DAC/TCG, gates, skip distance) & ACFM basics •
Reporting, anomaly coding, workpack planning & QA/QC •
Asset terminology & feature IDs (pipeline/risers/trees/manifolds) ✓
Visual inspection: GVI/CVI, cleaning standards, measurement & sketching ✓
Photography/video with overlay & commentary ✓
CP survey (Ag/AgCl/seawater), interpretation & troubleshooting ✓
UDTM (thickness) — setup, calibration, limits ✓
ID & %‑cover Marine growth methods (SACFOR, quadrats, line‑intercept) ✓
Fluorescent/visible MPI (field fundamentals) ✓
Toe‑grinding (method, acceptance, re‑inspection) ✓
Advanced UT (DAC/TCG, gates, skip distance) & ACFM basics ✓
Reporting, anomaly coding, workpack planning & QA/QC •
Asset terminology & feature IDs (pipeline/risers/trees/manifolds) ✓ (supervise)
Visual inspection: GVI/CVI, cleaning standards, measurement & sketching ✓ (plan/assure)
Photography/video with overlay & commentary ✓ (QA)
CP survey (Ag/AgCl/seawater), interpretation & troubleshooting ✓ (review/trend)
UDTM (thickness) — setup, calibration, limits ✓ (QA)
ID & %‑cover Marine growth methods (SACFOR, quadrats, line‑intercept) ✓
Fluorescent/visible MPI (field fundamentals) ✓ (acceptance)
Toe‑grinding (method, acceptance, re‑inspection) ✓ (sign‑off)
Advanced UT (DAC/TCG, gates, skip distance) & ACFM basics ✓ (method selection)
Reporting, anomaly coding, workpack planning & QA/QC ✓
KP chainage; FJ‑### field joint; Anode (bracelet/sled); CWC (concrete weight coating); FJC (field joint coating); ILT (in‑line tee); PR/PL (pig receiver/launcher); SSIV; Hot‑tap; Expansion spool.
PLET (termination), PLEM (manifolded termination), Manifold header, Guide base, Tie‑in porch, SUTA/SDU (umbilical termination/distribution), Stab plate.
TTR/SCR (top‑tensioned/flexible catenary riser), Riser clamp/fairlead/porch, Tree/X‑mas tree, Gooseneck/J‑tube.
Mudmats, Concrete mattresses, Mattress pins, Rock dump, Span (free length), Span shoulders.
Hazards (current/impact), communications, tooling, cleaning limit.
Record conditions.
Identify features, gross damage, spans, coating holidays, anodes.
Local clean (minimal; avoid coating damage), expose weld toes/defects.
Rule/scale, pit/radius gauge; record KP & clock‑face.
Orthogonal + obliques; scale in frame; captions.
Structured (see §11 templates).
Defect type, sizes, evidence, acceptance/reference, recommended action.
Ag/AgCl/seawater; verify against standard; keep porous tip clean.
preference for contact pad/near‑contact to reduce IR drop.
readings more negative than ≈ −0.80 V (Ag/AgCl/seawater) often indicate protection. Use project criteria.
clean small pad if needed → stabilise reading → log KP/depth/temp/flow → compare trends near anodes/joints.
erratic = cable fault/coating holiday; less‑negative near defects = poor contact/IR drop; big gradients = broken continuity or shielding.
Deliverables: calibration sheet, raw logs, overlay video of contact points, map of KP readings.
Velocity (steel): ~5920 m/s. Use echo‑to‑echo to cancel coating delay.
Calibration: step‑wedge → set velocity → verify on bare metal pad.
Technique: clean/flat pad; consistent pressure; repeat 3× at each point; note temperature.
Limitations: roughness/marine growth; tight radii/small OD; high flow; geometry.
Back‑of‑slate calc example: t(mm) ≈ (v (m/s) × time(µs))/2000. E.g., 1.70 µs → ~5.0 mm.
Superabundant, Abundant, Common, Frequent, Occasional, Rare.
Hydroid stings; sharp shells; silt/backscatter management for imagery.
UV‑A ≈ 365 nm; dark adaptation ~5 min; keep white light low (use tent/hood). Verify UV intensity at working distance.
Yoke (AC/DC) or prods; two directions (perpendicular to expected crack). Confirm with QQI/pie gauge; ensure firm pole contact (no lift‑off).
Correct concentration, agitate, control flow; streaming water washes particles off.
Sharp, continuous linear fluorescence → crack‑like; geometry edges/background → non‑relevant; re‑magnetise in second direction.
Demagnetise if required; clean; restore coating; complete records (UV/lux, QQI photos, settings).
remove small surface cracks & reduce stress concentration with a smooth blended radius over ≥150 mm length.
hydraulic grinder, suitable burrs/flap; gauges; tethers; PPE; staging for current.
mark length → light passes (avoid heat/blueing) → cross-check profile → deburr → avoid grooves aligned with stress.
continuous blend; minimum radius per spec; re-inspect (MPI two directions / ACFM); document before/after with scale.
Plan skip distances; set gates; use DAC/TCG for consistent sensitivity; mitigate dead zone (delay line/dual‑element). Angle-beam 45–70° common.
Through-coating surface crack detection with length/depth estimates; maintain stable lift‑off; manage EM noise; great when light control/cleaning is limited.
Scope, hazards, permits, roles; tools & calibration; dark‑room plan for fluorescent MPI; grind workpack with hold points.
Overlay-rich video; captioned stills with scale; measurement tables; UV/lux & QQI records; UT/ACFM calibration files; anomaly log.
CVI → MPI → ACFM → UT depending on coating, access, lighting, and objective.
Objective language; KP/clock-face; sizes with method; acceptance criteria cited; clear recommendation & priority.
Unique IDs, filenames tied to KP/feature; operator IDs; settings; backups; sign‑offs.
Workpack/permits
Mark ≥150 mm
Secure staging
Light passes
Control heat
Check profile/radius
Deburr
MPI/ACFM re‑inspect
Photos before/after with scale
Sign‑off
"At KP 12.300 / FJ‑084 / 9 o'clock, weld toe cleaned; linear indication ~45 mm long detected by fluorescent MPI (UV-A verified). Second direction confirms; demag applied. Recommend: toe-grind ≥150 mm and re‑inspect."
"UDTM on cleaned pad indicates 7.6 mm (echo-to-echo, v=5920 m/s, 18°C). Repeat x3: 7.6/7.5/7.6 mm."
MCQ: read stem → predict → then scan options; eliminate two; watch units (mm vs m); beware "always/never."
Short answers (3–4 marks): define + two key points + one practical example.
Extended answers: open with scope/purpose, then ordered steps; finish with acceptance & documentation.
Time‑box: don't stall mark and return. Use sketches for weld geometry/beam paths.
Common pitfalls: missing overlay IDs; no scale; forgetting second magnetisation; poor CP contact; UDTM without echo‑to‑echo; unblended grind grooves.
Match your answers to project criteria (potentials, acceptance radii, lighting limits).
Use objective language and evidence.
Safety first: tool control, current management, visibility, and comms.
Good luck — and remember: clean, measure, evidence, recommend.
High-resolution underwater cameras with overlay capabilities, video systems with timestamp and depth data, lighting systems with variable intensity control, and measurement scales.
Pit gauges, calipers, radius gauges, ultrasonic thickness meters, CP reference electrodes, and digital multimeters with waterproof housings.
Hydraulic grinders, wire brushes, needle guns, water jets, and specialized marine growth removal tools designed for underwater use with proper tethering.
Toe cracks, lack of fusion, porosity, undercut, and excessive reinforcement. Typically require MPI or ACFM for confirmation after visual identification.
General surface corrosion, pitting, crevice corrosion at joints, and galvanic corrosion at dissimilar metal interfaces. Measure depth with pit gauges and document with scale.
Impact damage, abrasion, deformation, and free spans exceeding allowable limits. Document with measurements and multiple angle photographs.
Disbondment, holidays, blistering, and mechanical damage. Check for correlation with CP readings and document extent with measurements.
DIVER WELL