Exam format, study system, hardest topics and practical assessment tips
The CSWIP 3.1u exam tests your ability to identify defects, understand inspection principles, and work safely underwater. It is not designed to trick you. It expects precision and safety.
This guide walks you through the exam format, the topics most candidates struggle with, and how to use the NDTPrep 3-stage study system to prepare. Start with the free Welding Defects and Terminology Practice Exam, then work through Interactive Theory, then Q&A, then Flashcards in module order. The 3.1u Complete Study System bundles all three.
Two parts: a written exam and a practical assessment. Both must be passed.
| Component | Format | Duration | Pass Mark |
|---|---|---|---|
| Paper A: General | 50 multiple choice | 75 minutes | 70% |
| Paper B: Sector Specific | 50 multiple choice | 75 minutes | 70% |
| Practical Assessment | 5 inspection tasks + CCTV | 180 minutes (approx) | Pass/fail |
Identify and describe corrosion, cracks, and structural defects on steel samples.
Set up reference electrode, take stable readings, interpret against standards (-800 to -1100 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. Create a photo mosaic showing the overall structure and detailed close-ups of welds.
Narrate underwater video of actual welds, joints, and structural components using correct NDT terminology. Describe what you see: defect location, size, type, and condition, as you would on a real dive.
This is how successful divers use NDTPrep to pass their exam. For what each stage does and why the order matters, see The NDTPrep Study System.
Work one module at a time through all three stages before you move on:
Certified 3.1u Inspection Diver
The system stacks by design. Free resources build foundation. The 3-stage loop gives you breadth and retrieval practice offshore. The official course adds tank time and practical competence. Daily drilling locks it in. The CSWIP manual fills gaps. Then you pass.
These topics show up on both papers and are where most marks are lost. Not because they're complex, but because divers often get the terminology or concept wrong.
Why zinc protects steel. How sacrificial anode and ICCP systems work. What CP readings mean. The galvanic series. This is 15-20% of the exam.
Not "bad weld." It is "lack of sidewall fusion" or "centre-line crack." Wrong terminology costs marks. Know the defect types cold.
Understanding how depth of field, focal length, and lighting affect your image quality. Know what settings produce clear, usable documentation underwater.
Ready to start preparing? The 3.1u Complete Study System includes Interactive Theory, Q&A Exam Prep, and the Flashcard Trainer. Theory covers CP, welding defects, and photography in depth. Already have theory covered? The Exam Bundle is Q&A and Flashcards only.
★★★★★ 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
You have never sat a CSWIP exam. You have no idea what is in store. Here is how to prepare.
Offshore (1-2 months before the official course): Start getting familiar with the material while you have downtime. Download the free Weld Defects eBook and work through the free Welding Defects and Terminology Practice Exam. Terminology is everything on CSWIP exams, and most divers get it wrong the first time because they do not know what they are looking for yet.
Get the 3.1u Complete Study System (Theory, Q&A, and Flashcards together) or start with Interactive Theory on its own. Work one module through all three stages before you move on. Read every Q&A explanation. That is where the real learning happens. Then hit the Flashcard Trainer on the gaps Q&A flagged. It sticks better than passive reading.
Do the official 3.1u CSWIP course: Sit the approved CSWIP training centre course. Instructor-led. Structured. Do the homework they give you. The exam is right after. You need to lock it in during the course.
Study for your exam (during and immediately after the course): The course teaches you the material. The CSWIP manual is your reference. It is where the exam questions come from. When a topic does not stick, run that module again in Theory, then Q&A, then Flashcards from your Complete Study System. I built this loop for exam focus.
At the end of each day, drill the modules covered in class. 15-20 minutes minimum. Theory revisit on weak spots, then Q&A, then Flashcards while it is fresh. Weak spots show you where to focus harder before you walk into the exam room.
You have your 3.1u cert. Five years have passed. Time to renew. Start with the two free resources: the Weld Defects eBook and the free Practice Exam to refresh your fundamentals before the official refresher course.
Offshore (1-2 months before the refresher course): Run the Complete Study System while you have downtime. Start with Theory on rusty topics (CP, corrosion, welding defects). Q&A will show what faded. Flashcards lock it back in. Terminology sticks, but not perfectly after five years. You will spot what is rusty fast. Reference the CSWIP manual when something does not click.
Do the one-day refresher course: This covers both theory and practical. Some time in class, some time in the tank. You review the material and get hands-on: visual inspection, CP measurement, UT, photography, CCTV commentary, just like the real exam. The instructor catches your bad habits. They give you class handouts with tips on what to study before the exam.
The day after the course (before the exam): Book your exam two days after the refresher. That extra day is gold. The class handouts tell you exactly what to focus on. Use that window. Hit Theory, Q&A, and Flashcards on those specific topics. This is where the loop works hardest. You are drilling fresh info while it is still sharp. Your brain locks it in fast.
Then sit the exam: You are ready. You refreshed theory, drilled practical in the tank, and refined everything in 48 hours. That is 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.
Already have theory covered? Exam Bundle (Q&A + Flashcards only). Read the Study System guide.