--1.45 Color Coordination

1.45 Color Coordination

If making custom whips, hose assemblies, and cylinder markings, it is useful to use color codes that are consistent throughout the dive spread. In general, the only consistent coloring scheme that is widespread is green to indicate oxygen.

Color coordination should be simple, intuitive, and follow some consistency with established standards of practice in both diving and among industrial gas suppliers. The objective should be to create easy and obvious identification of gas contents from afar, with a quick glance, or while under stress during a dive.

This effort is particularly important when diving in teams or when staging cylinder depots for extended range intervention. Once deployed in the water, it is often impractical to view a small cylinder contents label; therefore, large maximum operating depth (MOD) markings have been considered standard to-date. However, this is also inherently confusing and poses several questions:

1. Is the MOD in feet or meters?

2. What is the actual gas contents?

3. Whose cylinder is it?

Granted, these are issues that can be discussed prior to a dive, however in my view remain overly complicated. Much like NOAA nitrox “standard gases” being EAN32 and EAN36, a standardized set of mixed-gas CCR diluent gas coding should be considered - not for specific mixes per se, but rather broad mix classifications. There are certainly variations to be had and good reasons for quick and dirty fills in remote locations; though on a job site, simple and consistent is critical to avoid confusion. For working dives, we want the diver to view the equipment as simple and as intuitive as possible to operate. Self-reliance and self-checks are still an absolute requirement, though by standardizing gas mixtures and related cylinder markings, the element of trust and confidence is elevated amongst dive team members both within the water, and among the topside team during pre-dive preparations.