Exam format, study system, hardest topics & practical assessment tips
The CSWIP 3.1u exam tests your ability to identify defects, understand inspection principles, and work safely underwater. It's not designed to trick you — it expects precision and safety.
This guide walks you through the exact exam format, the topics most candidates struggle with, and how to use our NDTPrep 3.1u Exam Bundle to prepare efficiently. Start with the FREE Welding Defects and Terminology Practice Exam to build your foundation.
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 –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. 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.
The system stacks by design. Free resources build foundation. Bundle gives you breadth. Official course adds depth. Daily drilling locks it in. The TWI 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's "lack of sidewall fusion" or "centre-line crack." Using 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 Exam Bundle includes the Q&A Exam Prep course and Flashcard Trainer — everything you need to cover all three hardest topics and more.
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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've never sat a CSWIP exam. You have no idea what's in store. Here's how to prepare.
Offshore (1-2 months before the official course): Start getting familiar with the material while you've got 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 don't know what they're looking for yet.
Grab the 3.1u Exam Bundle — it includes both the Q&A Exam Prep course and the Flashcard Trainer in one purchase. Work through the Q&A a couple of times. Read every explanation — that's where the real learning happens. Then hit the Flashcard Trainer and get comfortable with how active recall works. 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 TWI CSWIP Manual is your reference — it's the official study guide and where the exam questions come from. When a topic doesn't stick, use the Flashcard Trainer and Q&A from your bundle to drill it. Our system is built for exam focus.
At the end of each day, drill the Flashcards on the modules covered in class. 15-20 minutes. Focus on what you learned that day while it's fresh. Test yourself with Q&A again on those same topics. Weak spots show you where to focus harder before you walk into the exam room.
You've got your 3.1u cert. Five years have passed. Time to renew. Start with our 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 TWI refresher course): Go through the 3.1u Exam Bundle — Q&A and Flashcard Trainer — while you've got downtime. Daily drills. Terminology sticks, but not perfectly after five years. You'll spot what's rusty fast. Reference the CSWIP Manual when something doesn't click.
Do the TWI one-day refresher course: This covers both theory and practical. Some time in class, some time in the tank. You'll 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 from TWI tell you exactly what to focus on. Use that window — hit the Flashcard Trainer and Q&A in your bundle on those specific topics. This is where the system works hardest. You're drilling fresh info while it's still sharp. Your brain locks it in fast.
Then sit the exam: You're ready. You've refreshed theory, drilled practical in the tank, and refined everything in 48 hours. 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.
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