Exam format, MPI practical breakdown, weld toe grinding requirements, the hardest topics and how to prepare as a working inspection diver.
The 3.1u gets divers into inspection work. The 3.2u is where it gets serious. You're moving from observation-based visual inspection into hands-on NDT — running MPI underwater, interpreting what you find, and physically grinding welds to a specification.
The theory is more demanding, the practical is hands-on under exam conditions, and the examiner expects precision. Divers who treat this as a straightforward step up from 3.1u often get caught out by the depth of NDT theory required and the strict tolerances on the practical.
This guide covers exactly what's in the exam, where candidates lose marks, and how to prepare properly — based on the official CSWIP exam requirements document (7th Edition, June 2024).
The 3.2u exam has two elements: a multiple choice theory exam and a hands-on practical assessment. You must pass both. A strong performance in the theory doesn't save you if the practical doesn't meet standard.
| Element | Format | Questions / Task | Time | Pass Mark |
|---|---|---|---|---|
| Paper A — General | Multiple choice | 50 questions — MPI theory, ultrasonics, corrosion protection, visual inspection, NDT general | 75 min | 70% |
| Paper B — Sector Specific | Multiple choice | 50 questions — subsea MPI application, equipment deployment, sensitivity variables, limitations | 75 min | 70% |
| Practical — MPI | Hands-on assessment | MPI on three ferritic steel welds using various magnetisation techniques with fluorescent inks and UV light | Practical | Must pass |
| Practical — Grinding | Hands-on assessment | Weld toe grinding of a 150mm weld length to a specific written requirement | Practical | Must pass |
Both theory papers (A and B) are multiple choice, 50 questions each. Paper A covers general NDT principles. Paper B focuses specifically on subsea applications of those same techniques. You need 70% on each paper independently — you can't average them.
Below is the topic breakdown with an honest assessment of difficulty based on where candidates typically struggle.
The core technical focus of 3.2u. Covers principles of magnetism, yoke and coil techniques, ink types, UV light requirements, sensitivity checks, and defect interpretation. Expect this to dominate both papers.
Paper B digs into the specifics of running MPI underwater — coil positioning, limitations in subsea environments, how sea conditions and temperature affect sensitivity, and what the diver must check before starting work.
A-scan principles, calibration blocks, probe types, sound velocity, angle beam inspection. More theoretical than 3.1u ultrasonic thickness measurement. Understand what you're seeing on the A-scan display.
Cleaning standards for inspection, surface preparation, SA grades, cleaning areas to the correct size, and how surface condition affects NDT results. Directly linked to the practical.
Builds on 3.1u. CP system design, anode types, potential readings and what they mean, coating systems and how degradation affects inspection approach.
Covers radiography, eddy current testing, and other NDT methods used offshore. You won't run these techniques but the exam expects you to know their principles, advantages, and limitations.
Ready to start preparing? Our 3.2u Bundle covers all six topic areas with targeted exam-style questions and explanations — plus the free resources to build your foundation first.
⭐⭐⭐⭐⭐ 5-Star Review
Super Informative and Helpful
Wow! What a great way to gain inspection knowledge. Really helpful and really assists in retaining information. Thanks NDTPrep!
— Vincent Ian Le Roux, CSWIP 3.1u Student
The 3.2u practical has two elements. Both must pass. For the five year renewal, the full 3.1u practical components are added on top — see the renewal callout below.
Identify and describe corrosion, cracks, and structural defects on steel samples.
Set up reference electrode, take stable readings, interpret against standards (–800 to –1050 mV Ag/AgCl).
Calibrate gauge, take thickness readings in a grid pattern, record data systematically.
Compose clear, properly scaled photos of defects showing location, size, and type.
Narrate underwater video of actual welds, joints, and structural components using correct NDT terminology. Describe defect location, size, type, and condition.
MPI on three ferritic steel welds using various magnetisation techniques with fluorescent inks and UV light. Select the correct technique for each weld orientation.
Grind a 150mm weld length to a specific written requirement. Smooth blend, no score marks, stay within depth limits.
The practical above applies to the initial 3.2u exam. If you're sitting the five year renewal, the practical scope is significantly broader. It includes all the 3.1u components plus the 3.2u-specific tasks:
Maximum diving time for the renewal practical is four hours. You also need to provide evidence of a minimum of 100 hours underwater inspection experience over the five year certificate period before you can sit the renewal.
These are the areas where 3.2u candidates consistently struggle — either because the concept is genuinely complex, or because the exam tests it in a way that trips people up.
70% is the pass mark on both papers — that's 35 out of 50. You can afford to miss 15 questions and still pass. That means you don't need to know everything perfectly. You need to know the core content well and manage your time.
This is how successful divers use NDTPrep to pass their 3.2u exam.
The system stacks by design. Free resources build the weld defect foundation. The 3.2u Bundle covers all four courses — 3.1u Q&A, 3.1u Flashcard Trainer, 3.2u Q&A, and 3.2u Flashcard Trainer. Both levels of theory need to be sharp. The official course adds the practical. Daily drilling locks it all in. Then you pass.
You've got your 3.1u. Now you're stepping up to 3.2u. The exam is more technical — MPI theory, subsea NDT application, and two hands-on practicals. Here's how to prepare.
Offshore (1–2 months before the official course): Start with the two free resources — download the Weld Defects eBook and work through the FREE Welding Defects Practice Exam. These build the defect vocabulary that feeds straight into MPI interpretation.
Then grab the 3.2u Bundle — it includes all four courses. Start with the 3.1u Q&A Course and 3.1u Flashcard Trainer to sharpen the foundation topics that carry into Paper A — corrosion, CP, visual inspection, welding defects. Don't skip this step. If it's been a couple of years since your 3.1u, those topics need refreshing before you add the 3.2u content on top.
Then work through the 3.2u Q&A Course and 3.2u Flashcard Trainer. MPI theory and the subsea application questions in Paper B are where most candidates lose marks. The more familiar the concepts are before you walk into the classroom, the more the official course reinforces rather than introduces.
Do the Official 3.2u CSWIP Course: Sit the approved CSWIP training centre course. Classroom theory plus time in the tank on MPI and grinding. Your six hours practical experience requirement is logged here. The exam follows shortly after — do the homework, stay focused.
Study During and After the Course: Drill all four courses in the Bundle daily — 3.1u Q&A, 3.1u Flashcards, 3.2u Q&A, 3.2u Flashcards. Work on the modules covered each day while they're fresh. Weak spots show you exactly where to focus before exam day.
Then sit the exam: Theory in the morning, practical in the tank. You've drilled both theory levels and put hands on the equipment. That's the preparation.
Your 3.2u is due for renewal. Five years out of the exam room means some of the detail has faded. The renewal practical is broader than the initial — it includes the full 3.1u practical components on top of MPI and grinding.
Offshore (1–2 months before the TWI refresher course): Start with the two free resources to warm up — the Weld Defects eBook and the FREE Welding Defects Practice Exam. Then work through all four courses in the 3.2u Bundle — 3.1u Q&A, 3.1u Flashcard Trainer, 3.2u Q&A, and 3.2u Flashcard Trainer. You'll spot fast what's rusty. The renewal theory exam covers both 3.1u and 3.2u content — both levels need to be sharp.
Do the TWI refresher course: Theory review and tank time covering both 3.1u and 3.2u practical components — visual inspection, CP, UT, photography, CCTV commentary, MPI, and grinding. The instructor catches your bad habits. Use the class handouts to guide your final study.
The day after the course: Book your exam two days after the refresher. Hit all four Bundle courses on the topics highlighted in your class notes — 3.1u Q&A, 3.1u Flashcards, 3.2u Q&A, 3.2u Flashcards. That window is where the system works hardest — you're drilling fresh material while it's still sharp.
Then sit the exam: You've refreshed both theory levels, drilled all four courses, and logged practical time in the tank. That's the edge.
NDTPrep is an independent exam preparation platform. Not affiliated with or endorsed by TWI Certification Ltd or CSWIP. All certification training and examinations are administered by approved CSWIP training centres. Exam format and requirements are based on the most recent certification document available at time of publication and may change. Always confirm current requirements directly with TWI Certification Ltd at twitraining.com.
Built by a diver, for divers. Study from anywhere — offshore, on leave, or between rotations.