NAUI Cheat Sheet 2026

The 30 highest-yield NAUI facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Decompression sickness (DCS) Type II involves which body systems, making it more serious than Type I? → Neurological and cardiopulmonary systems
2. When storing a wetsuit long-term, which method best preserves the neoprene? → Hang it on a wide hanger in a cool, dark area
3. What does the term 'annual visual inspection' (AVI) of a scuba cylinder refer to? → A professional inspection of the interior and exterior with updated sticker
4. Which ocean zone receives sufficient sunlight to support photosynthesis? → Euphotic zone
5. What role does peer review play in the NAUI design process? → It provides independent verification, catches errors, and enhances overall quality
6. Why is the buddy system important in scuba diving? → To provide immediate assistance during emergencies
7. During a drift dive, divers should maintain contact with the group primarily by: → Staying within visual range and matching depth
8. What is the function of a safety stop during ascent? → To allow for nitrogen elimination
9. What does visual inspection of a scuba tank check for? → Internal and external damage like corrosion or cracks
10. When a panicked diver on the surface refuses to let go of you and pulls you underwater, what is the FIRST action you should take? → Submerge to escape their grip
11. A diver's fin strap breaks mid-dive trip. Which field repair is most practical and safe? → Use a zip tie as a temporary strap replacement
12. What is the purpose of inspecting O-rings on scuba tanks? → To ensure a proper air seal and prevent leaks
13. Which type of regulator configuration is most appropriate for technical and cave diving where gear entanglement risk is higher? → DIN regulators with a streamlined hose routing
14. What documentation is MOST critical to maintain for safety compliance in the National Association of Underwater Instructors Certification field? → Incident reports, training records, and inspection logs
15. Which condition results from rapid ascent without proper decompression? → Decompression sickness
16. Carbon monoxide (CO) in a scuba tank is particularly dangerous because it does what in the body? → Binds to hemoglobin with 200× greater affinity than oxygen, preventing O2 transport
17. What does a slow ascent rate help prevent? → Decompression sickness
18. A diver finds their wetsuit zipper is difficult to close before a dive. What is the best field remedy? → Apply beeswax or a zipper lubricant specifically designed for dive zippers
19. Coral reefs cover less than 1% of the ocean floor but support what approximate percentage of all marine species? → 25%
20. A diver who surfaces far from the boat in a current should: → Inflate SMB, conserve energy, and signal for pickup
21. What primarily drives surface ocean currents? → Wind patterns and differences in water density
22. What does the NAUI acronym 'SEABAG' represent in the context of pre-dive safety checks? → A mnemonic for checking S-BCD-Air-BC-Adequate-Gear
23. What is bioluminescence as observed in many deep-sea marine organisms? → Light produced through chemical reactions within the organism
24. How frequently should ongoing assessments be conducted in National Association of Underwater Instructors Certification practice? → At regular intervals based on established protocols and as conditions change
25. Which maintenance step is crucial after every saltwater dive? → Rinsing with fresh water
26. Which of the following best describes the term 'residual nitrogen' in dive planning? → Excess nitrogen dissolved in tissues from a previous dive
27. A diver notices their buddy is not responding to signals and appears rigid underwater. The first action should be: → Check for consciousness by tapping and observing
28. What happens to the volume of a flexible air pocket in a diver's body (like a sinus) during ascent if it cannot equalize? → It expands, potentially causing barotrauma
29. Why is continuous instructor training important in NAUI programs? → To stay informed and provide the best instruction
30. Which tool is essential for checking tank pressure? → Pressure gauge