PADI Enriched Air Nitrox Diving 5

Question 1

What information must be recorded on a nitrox cylinder before it is approved for diving?

Accepted Answer

Analyzed oxygen percentage, MOD, and diver's initials or signature

Answer

The cylinder must be tagged with the verified FO₂, the calculated MOD, and the analyzing diver's initials to confirm the analysis was performed.

Question 2

Why do enriched air divers generally require less weighting than when diving air at the same depth?

Accepted Answer

This is a misconception; weight requirements depend on exposure suit and diver physiology, not the gas mix

Answer

Weighting is determined by the diver's buoyancy characteristics and exposure suit, not by whether they are breathing nitrox or air.

Question 3

Which type of oxygen toxicity is most relevant to breath-hold (free) divers rather than scuba divers?

Accepted Answer

Pulmonary (lung) toxicity

Answer

Pulmonary toxicity develops from prolonged lower-level oxygen exposure and is more of a concern in technical/surface-supply diving; CNS toxicity is the primary scuba concern.

Question 4

A student diver asks why they cannot dive a rented EANx36 cylinder without an Enriched Air certification. What is the most accurate explanation?

Accepted Answer

Without training, the diver doesn't know the correct MOD, CNS limits, or analysis requirements, creating serious safety risks

Answer

Enriched air certification teaches oxygen partial pressure limits, MOD calculation, CNS toxicity recognition, and proper cylinder analysis — all critical safety knowledge.

Question 5

What happens to the no-decompression limit (NDL) as the oxygen percentage in a nitrox mix increases (at a constant dive depth)?

Accepted Answer

NDL increases because less nitrogen means slower tissue saturation

Answer

Higher oxygen fraction means lower nitrogen fraction, so tissues absorb nitrogen more slowly and the diver can stay longer before reaching decompression obligation.

(PADI) Certified Professional Association of Diving Instructors Diver Practice Test

(PADI) Certified Professional Association of Diving Instructors Diver Practice Test

PADI Enriched Air Nitrox Diving 5