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. Which ocean zone receives sufficient sunlight to support photosynthesis? → Euphotic zone
4. What role does peer review play in the NAUI design process? → It provides independent verification, catches errors, and enhances overall quality
5. Why is the buddy system important in scuba diving? → To provide immediate assistance during emergencies
6. What is the function of a safety stop during ascent? → To allow for nitrogen elimination
7. What does visual inspection of a scuba tank check for? → Internal and external damage like corrosion or cracks
8. 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
9. What is the purpose of inspecting O-rings on scuba tanks? → To ensure a proper air seal and prevent leaks
10. 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
11. Which condition results from rapid ascent without proper decompression? → Decompression sickness
12. What does a slow ascent rate help prevent? → Decompression sickness
13. Coral reefs cover less than 1% of the ocean floor but support what approximate percentage of all marine species? → 25%
14. A diver who surfaces far from the boat in a current should: → Inflate SMB, conserve energy, and signal for pickup
15. What primarily drives surface ocean currents? → Wind patterns and differences in water density
16. What is bioluminescence as observed in many deep-sea marine organisms? → Light produced through chemical reactions within the organism
17. 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
18. Which maintenance step is crucial after every saltwater dive? → Rinsing with fresh water
19. Which of the following best describes the term 'residual nitrogen' in dive planning? → Excess nitrogen dissolved in tissues from a previous dive
20. 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
21. 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
22. Why is continuous instructor training important in NAUI programs? → To stay informed and provide the best instruction
23. Which tool is essential for checking tank pressure? → Pressure gauge
24. Which symptom most clearly indicates a regulator second stage needs professional servicing? → A faint hiss of continuous free-flow at the surface
25. What does a milky or cloudy appearance inside a diving mask lens typically indicate? → Salt residue from inadequate post-dive rinsing
26. Which personal protective equipment (PPE) principle applies to ALL NAUI certified professionals regardless of their specific role? → PPE must be properly fitted, maintained, and replaced as needed
27. What is the FIRST consideration when designing a solution in National Association of Underwater Instructors Certification practice? → Understanding requirements, constraints, and stakeholder needs
28. What is the primary cause of coral bleaching? → Elevated water temperatures causing coral to expel zooxanthellae algae
29. What is the PRIMARY purpose of obtaining NAUI certification in National Association of Underwater Instructors Certification? → To demonstrate verified competency and adherence to professional standards
30. A diver notices the o-ring on their cylinder valve is cracked and dry. What is the correct action? → Replace the o-ring with one of the correct size and material before diving