ENRICHED AIR NITROX CORE EXAMINATION
2026 QUESTIONS AND ANSWERS SURE A+
✔✔Nitrox and the acronym EANx solely refer to mixtures with oxygen concentrations
(FO2) higher than:
A) 36%
B) 21%
C) 32%
D) 40% - ✔✔21%
✔✔The major benefit of diving with nitrox is that it has a lower concentration of the gas
which limits our time at depth. This gas is:
A) Air
B) Nitrox
C) Oxygen
D) Nitrogen - ✔✔Nitrogen
✔✔Compared to air, Nitrox has a higher concentration of:
A) Air
B) Nitrogen
C) Carbon dioxide
D) Oxygen - ✔✔Oxygen
✔✔Which Gas adds a lot of benefits to multi-level Computer Diving?
A) Nitrox
B) Nitrogen
C) pure Oxygen
D) Air - ✔✔Nitrox
, ✔✔The recommended limiting ppO2 and maximum limiting ppO2 for recreational nitrox
dives are:
A) 0.21/ 0.16
B) 0.21/ 0.79
C) 1.3/ 1.6
D) 1.4/ 1.6 - ✔✔1.4/ 1.6
✔✔The best way to compare the levels of oxygen found in any mixture of the breathing
gas we breathe under water is to compare:
A) Amount of breathing gas in the cylinder
B) Partial Pressure of Nitrogen
C) The Dive plan
D) Partial Pressure of Oxygen - ✔✔Partial Pressure of Oxygen
✔✔Since CNS oxygen toxicity is among the greatest of risks in Nitrox diving, you must
be able to recognize:
A) Its positive aspects in deep diving
B) Its warning signs and symptoms, both in yourself and others
C) Its treatment
D) Its warning signs and symptoms, only in yourself - ✔✔Its warning signs and
symptoms, both in yourself and others
✔✔The chief sign of CNS oxygen toxicity, which can cause the loss of the second stage
and drowning is?
A) Joint Pain
B) Itchiness of the skin
C) Convulsions
D) Visual impairment - ✔✔Convulsions
✔✔How can the ppO2 of a breathing gas be calculated?
A) Divide ambient pressure by the fraction of oxygen (FO2) found in the breathing gas
B) Multiplying cylinder pressure by the fraction of Nitrogen (FN2) in the cylinder
C) Multiplying air pressure by the fraction of oxygen (FO2) found in the breathing gas
D) Multiplying ambient pressure by the fraction of oxygen (FO2) found in the breathing
gas - ✔✔Multiplying ambient pressure by the fraction of oxygen (FO2) found in the
breathing gas
✔✔The risk of CNS oxygen toxicity becomes more substantial above:
A) 300 meters / 1000 ft of altitude
2026 QUESTIONS AND ANSWERS SURE A+
✔✔Nitrox and the acronym EANx solely refer to mixtures with oxygen concentrations
(FO2) higher than:
A) 36%
B) 21%
C) 32%
D) 40% - ✔✔21%
✔✔The major benefit of diving with nitrox is that it has a lower concentration of the gas
which limits our time at depth. This gas is:
A) Air
B) Nitrox
C) Oxygen
D) Nitrogen - ✔✔Nitrogen
✔✔Compared to air, Nitrox has a higher concentration of:
A) Air
B) Nitrogen
C) Carbon dioxide
D) Oxygen - ✔✔Oxygen
✔✔Which Gas adds a lot of benefits to multi-level Computer Diving?
A) Nitrox
B) Nitrogen
C) pure Oxygen
D) Air - ✔✔Nitrox
, ✔✔The recommended limiting ppO2 and maximum limiting ppO2 for recreational nitrox
dives are:
A) 0.21/ 0.16
B) 0.21/ 0.79
C) 1.3/ 1.6
D) 1.4/ 1.6 - ✔✔1.4/ 1.6
✔✔The best way to compare the levels of oxygen found in any mixture of the breathing
gas we breathe under water is to compare:
A) Amount of breathing gas in the cylinder
B) Partial Pressure of Nitrogen
C) The Dive plan
D) Partial Pressure of Oxygen - ✔✔Partial Pressure of Oxygen
✔✔Since CNS oxygen toxicity is among the greatest of risks in Nitrox diving, you must
be able to recognize:
A) Its positive aspects in deep diving
B) Its warning signs and symptoms, both in yourself and others
C) Its treatment
D) Its warning signs and symptoms, only in yourself - ✔✔Its warning signs and
symptoms, both in yourself and others
✔✔The chief sign of CNS oxygen toxicity, which can cause the loss of the second stage
and drowning is?
A) Joint Pain
B) Itchiness of the skin
C) Convulsions
D) Visual impairment - ✔✔Convulsions
✔✔How can the ppO2 of a breathing gas be calculated?
A) Divide ambient pressure by the fraction of oxygen (FO2) found in the breathing gas
B) Multiplying cylinder pressure by the fraction of Nitrogen (FN2) in the cylinder
C) Multiplying air pressure by the fraction of oxygen (FO2) found in the breathing gas
D) Multiplying ambient pressure by the fraction of oxygen (FO2) found in the breathing
gas - ✔✔Multiplying ambient pressure by the fraction of oxygen (FO2) found in the
breathing gas
✔✔The risk of CNS oxygen toxicity becomes more substantial above:
A) 300 meters / 1000 ft of altitude
