Gas Diving Mixes
Choose the best Mix for the dive.

Air dive for fish dives within NDL (No Decompression limit)
or
short shallow cave12 mt or less.

Then use Nitrox to increase the NDL, limit their MOD
(Maximum Operating Depth) to 30mt minding narcosis and
avoid decompression dives in this mixes at has proof
unpredictable in long exposures

For Deco dives you should use helium based mixes not
only to avoid narcosis, reduce PO2 (partial Oxygen
pressure) but also to have more predictable
decompression time tables.

Anyhow you must get properly educated and trained in the
use of these or any diving mixes.
Deco Gases
Name
 Oxygen
%
 Helium
%
 MOD
meters
 MOD
feet
 When to use it
O2
 100
 0
 6
 20
 Deco dives
Nitrox 50
 50%
 0
 21
 70
 Minimum Deco dives
50/25+
 50
 25
 21
 70
 High helium dives
35/25+
 35
 25
 36
 120
 High helium dives
19/35+
 19
 35
 60
 190
 Max Deco dives
16/45+
 16
 45
 75
 240
 Max Deco rb dives
Diving Gases
Name
 Oxygen
%
 Helium
%
 MOD
meters
 MOD
feet
 When to use it
Air
 21
 0
 30
 30
 short NDL dives never on
stages Max depth 30 mt
32
 32
 0
 30
 120
 Increased NDL max 30mt
30/30 or
25 /25
 30 or 25
 30 or 25
 36
 120
 Deco dive in 20-40mt range
18/45
 18
 45
 60
 190
 Deco dive 36-55mt range
15/55+
 15
 55
 75
 240
 Deco dive 55 -70mt range
12/70+
 12
 70
 90
 300
 Deco dive 70 - 85mt range
8/75+
 8
 75
 140
 400
 Deco dive from 85mt
Cave Explorer Knowledge Base