The FlowState Way: Training Philosophy, Policies & Procedures

Gas is the one component of a dive that cannot be corrected once the descent has begun. Trim, propulsion, and navigation can all be adjusted underwater. What a diver is breathing cannot. This policy exists to remove assumption from that single, unforgiving variable.

Every Diver, Every Cylinder, Every Dive - No Exceptions

Every diver analyses every cylinder they intend to breathe from, before every single dive, without exception. This is the entire policy stated plainly, and everything below is detail in service of that one rule. It does not matter whether the diver is a candidate on their first Genesis session or a Tier 4 Mentor with decades of experience. It does not matter whether a teammate has already checked their own cylinder, whether the fill station has a reputation for reliability, or whether the dive is a routine shallow session or a demanding technical profile. The rule does not bend for convenience, familiarity, repetition, or trust. Every diver. Every cylinder. Every dive.

This is not a shared or delegable task. No diver breathes from a cylinder that they, personally, have not analysed - regardless of what the label already says, who handed it to them, or how many times that exact cylinder has been used correctly before.

Applies Identically Regardless of Gas

This applies uniformly no matter what the cylinder is expected to contain. Air, nitrox, trimix, or any other mixture is treated identically: unverified until the diver about to breathe it has personally confirmed it themselves. A cylinder is never considered having the correct gas solely on the basis of a label already attached to it, unless that label is your own and was applied as the result of a successful analysis. Nor should it be accepted based solely on a fill station’s routine practice or a diver’s previous experience with that specific supplier or site.

Mandatory Timing

Gas analysis is one of the very first actions performed in any dive preparation sequence, conducted before equipment assembly begins. The gas calculation is built around verified gas, not around an assumption that gets checked afterward as a formality.

The Verification Sequence

A proper analysis follows a consistent sequence, every time:

1. Visual confirmation of cylinder identity - checking that markings match the expected configuration and planned assignment before the analyser is ever applied.
2. Analyser calibration against a known reference gas, confirming the device itself is reading accurately before it's trusted for anything.
3. Controlled, stable gas flow across the sensor, with the reading allowed to settle rather than accepted from a transient or fluctuating value.
4. Immediate recording of the result - documented, not simply remembered.
5. Cross-check against the planned dive - confirming the verified gas is not only correctly identified, but appropriate for the profile it's intended for.

A reading taken without this sequence, or accepted without genuine engagement in what it means for the planned dive, has not satisfied this policy - regardless of whether a number was technically produced.

Cylinder Labelling Requirements

Every analysed cylinder is labelled clearly, durably, and legibly, in a manner resistant to water exposure and handling. A label must show:

• Oxygen fraction as measured.
• Maximum operating depth.
• The name or initials of the diver who performed the analysis.
• The date of analysis.

A label reflects the gas as analysed, never the gas as expected. Labelling communicates verified reality to the diver and their team - it is not a record of intention, and it is never written before the analysis that's meant to justify it.

Analysis Is Repeated, Not Assumed to Persist

Gas identity is not retained by assumption, and a prior analysis does not carry forward to a new dive under any circumstance. A cylinder analysed and labelled yesterday is re-analysed today, in full, before it is used again - even by the same diver, even if the cylinder has not left their sight, even if nothing appears to have changed. A label from a prior dive is historical information. It is never treated as current verification for a dive about to happen.

Team Cross-Checking Is Encouraged, Never a Substitute

Teammates cross-checking each other's analysed and labelled cylinders is strongly encouraged as an additional layer of safety, consistent with the team-based redundancy this document builds around elsewhere. It never replaces the individual diver's own analysis. A teammate's confirmation is a second check on an already-completed verification - it does not, under any circumstance, stand in for the diver's own responsibility to have personally analysed their own gas.

Why This Policy Admits No Exceptions

Gas composition cannot be detected by sight, smell, or feel. Without analysis, a diver has no sensory basis for confirming what they are actually breathing, and a gas error - unlike a navigation or communication error - cannot be corrected once a diver is already submerged and dependent on it. This is precisely why the policy is absolute rather than situational: the consequence of an unverified assumption does not scale gently with depth, and the one moment this rule would feel inconvenient to follow in full is exactly the moment it matters most. There is no dive, no diver, and no circumstance exempt from it.