Bottom Gas Selection

SCRET has a standard gas mix for appropriate depth ranges as follows:

General Guideline for any custom gas mix:

O2 PPO2 = 1.4 PPO2 MAX
N2 PPN2 = 2.6 PPN2 MAX
Total 4.0 MAX = 100fsw AED

Decompression Gas Selection

Bottle Marking Standards

Any and all gas mixtures used in diving operations are to be oxygen analyzed by the user prior to diving.

The actual analysis of the mixture is to be recorded with the MOD, date and initials, on the neck of the tank at 5:00 o clock postion. All tanks are marked with a contrasting paint or sticker for easy reading. All marking should be at least 3 inches tall.

MOD (at 3:00 and 9:00 oclock postion) and Divers initials (at 12:00 and 6:00 oclock) on tanks

Back-Gas marking

Back gas bottles cannot be marked with an MOD because they are the only multipurpose tank used. Back gas bottles should have horizontal markings with the users name or initials. Mix pressures and oxygen analysis should be marked on the tank necks.

Decompression and Stage bottle marking

All decompression and stage bottles will be marked as follows:

Consider the tank from above the valve looking down. The valve handle is at 9 o'clock, the regulator at 6 o'clock. At 9 o'clock position going from the top of the tank down is the numbers indicating the MOD. The MOD must not be obscured by the regulator or the stage rigging. At 3 o'clock position going from the bottom of the tank up is the numbers indicating the MOD. The MOD must not be obscured by the regulator or the stage rigging. At the 12 o'clock and 6 o'clock position is the diver's initials or name for tank identification.