3CHAPTER
4CHAPTER
TABLE OF CONTENTS
Preface .......................................................IV
About the NAUI nitrox diver course .....................iv
Responsibilities ......................................................v
Getting the most of this course .............................v
1CHAPTER
2CHAPTER
Introduction 2
Learning goals.......................................................4
What is nitrox?.......................................................4
A bit of history........................................................4
Why dive with enriched air nitrox ........................8
Common misconceptions about nitrox..............10
Myth 1: “Nitrox is for technical diving.”.........10
Myth 2: “Nitrox is for deep diving.” ................10
Myth 3: “If you dive with
nitrox you won’t get bent.”...........................10
Myth 4: “Nitrox is safer than air.”...................10
Myth 5: “If you dive with nitrox
you won’t get narcosis.”................................11
Myth 6: “It is hard to dive with nitrox.” .........11
Terminology ........................................................11
Knowledge review ................................................12
Gases & Gas Mixtures 14
Learning goals .........................................................16
What is air? ..............................................................16
Some facts about individual gases:.........................17
Oxygen (O2) .........................................................17
Nitrogen (N2) .......................................................17
Argon (Ar).............................................................17
Carbon dioxide (CO2) ..........................................18
Helium (He) & Neon (Ne) ...................................18
How gases behave ....................................................18
Boyle’s law: pressure, volume, and density .........19
Units of measurement .............................................19
Henry’s law: the solubility of gases .........................20
Dalton’s law: partial pressure in gas mixtures.......21
Converting between depth and pressure .................22
Converting between depth and
pressure by formula................................................23
Converting between depth and
pressure with a table...............................................24
Calculating partial pressures...................................24
Determining oxygen partial
pressure by table .....................................................26
The OCEANx calculator...........................................26
Knowledge review.....................................................27
The Physiology of
Diving and Nitrox 30
Learning goals.....................................................32
Nitrogen: narcosis and
decompression sickness......................................32
Nitrogen narcosis.................................................32
Decompression sickness .....................................33
Oxygen: the good and the bad...........................35
Oxygen and metabolism .....................................36
Physiological effects of
low oxygen levels (hypoxia) ..............................36
Physiological effects of high oxygen levels .......36
Central nervous system toxicity ..........................37
Managing oxygen exposure ................................38
Avoiding CNS toxicity ..........................................39
Knowledge review ................................................40
Choosing the Best
Nitrox Mix 42
Learning goals.....................................................44
Enriched air nitrox mixtures ..............................44
Maximum operating depth.................................44
Maximum operating depth by table...................45
Calculating maximum operating depth ............46
Using the OCEANx to establish MOD..................46
Choosing your “best mix” ..................................47
Best mix by table .................................................47
Calculating best mix ...........................................48
Using the OCEANx to establish best mix ............48
Knowledge review ................................................50
VI
NAUI Nitrox Diver
Table of Contents