Totnes Sub Aqua Club

Nitrox mixes

Buddy diver

Here are the maximum operational depths (MOD) in metres for various Nitrox mixes and oxygen allowances.

fO2

1.3

1.4

1.5

1.6

21%

52

57

61

66

22%

49

54

58

63

23%

47

51

55

60

24%

44

48

53

57

25%

42

46

50

54

26%

40

44

48

52

27%

38

42

46

49

28%

36

40

44

47

29%

35

38

42

45

30%

33

37

40

43

31%

32

35

38

42

32%

31

34

37

40

33%

29

32

35

38

34%

28

31

34

37

35%

27

30

33

36

36%

26

29

32

34

37%

25

28

31

33

38%

24

27

29

32

39%

23

26

28

31

40%

23

25

28

30

 
A rough formula is given by:

Depth = ( ( Oxygen Allowance * 10) / Oxygen ratio ) - 10

eg. for Allowance of 1.4 and a Oxygen conc of 32%

Depth = ( (1.4 * 10) / 0.32) - 10

Depth = (14 / 0.32) - 10

Depth = 43.75 - 10

Depth = 33.75m