Enriched Air Diver

Question 1

Advantages of diving nitrox.

Answer 1

• Extends allowable bottom time.
• Reduces need to “Push” air no decompression limit.
• Reduces overall nitrogen load on multiple dives.

Question 2

How does EANx affect narcosis while diving?

Answer 2

There is no significant reduction of narcosis. Plan as you would when diving air.

Question 3

What’s the primary concern regarding enriched air nitrox and equipment?

Answer 3

Contact with high oxygen content may cause fire, explosion, and deterioration.

Question 4

Considerations for equipment when using enriched air up to 40% oxygen.

Answer 4

• Generally you can use standard scuba equipment.
• Use oxygen compatible lubricants.
• Follow manufacturers recommendations regarding using their equipment with enriched air.

Question 5

What are the potential hazards of improper enriched air filling procedures?

Answer 5

• Fire and explosion.

- Accurate filling.

Question 6

What are the maximum and contingency oxygen partial pressure limits?

Answer 6

• Maximum 1.4 ata / bar

- Contingency 1.6 ata / bar

Question 7

What is the primary hazard of exceeding oxygen exposure limits?

Answer 7

A fatal accident due to convulsing and drowning.

Question 8

What signs and symptoms may precede a CNS convulsion?

Answer 8

-Visual disturbance, Ear ringing, Dizziness.

Question 9

Do signs and symptoms always precede a CNS convulsion?

Answer 9

No, most occur without warning.

Question 10

Describe how you use a EANx dive computer to manage oxygen exposure.

Answer 10

• Set max PO2 at 1.4
• Stay within oxygen limits and above max depth for the blend your using.
• Avoid heavy exercise and carbon dioxide build up.
• Maintain buoyancy and depth control.

Question 11

What should you do if you exceed the oxygen exposure limits of your computer?

Answer 11

• Ascend immediately but slowly and end the dive.

- Do not dive for 24 hours, or as stipulated by the manufacturer.

Question 12

Who must personally verify the oxygen content in an enriched air cylinder before it is used?

Answer 12

The diver who will use the cylinder.

Question 13

What is the procedure for verifying an enriched air cylinder.

Answer 13

• Calibrate the oxygen analyzer.
• Ensure accuracy is within plus or minus 1%
• Compare the oxygen % with the % marked on the sticker or tag.

Question 14

What should you do if your dive computer fails during a dive?

Answer 14

• Ascend immediately.
• Safety stop at 15 feet.
• End the dive.

Question 15

What should you do if a diver convulses underwater?

Answer 15

Treat the situation as an unresponsive underwater emergency and bring the diver to the surface.

Question 16

What should you do if a diver is suspected of having DCI after an enriched air dive?

Answer 16

• Contact local emergency personnel and diver emergency services.
• Adminster emergency oxygen and first as as you normally would.

Question 17

What’s the primary benefit of using enriched air nitrox?

Answer 17

Less exposure to nitrogen than diving air.