Why is it crucial to have accurate tank markings and labels for EANx tanks?

Accurate tank markings and labels for EANx tanks are essential primarily to prevent confusion and to ensure that the correct gas mixture is used for dives. Enriched Air Nitrox contains a higher percentage of oxygen than regular air, which allows for longer bottom times and reduced nitrogen absorption. If a diver mistakenly uses a tank with the wrong gas mixture, it could lead to serious health risks such as oxygen toxicity or inadequate decompression during the ascent. Proper labeling ensures that divers can quickly and accurately identify the tank's gas content, enabling safer dive planning and execution.

While professionalism, the tank's age, and personal preferences might hold some relevance in the diving community, they do not have the same critical safety implications that accurate tank markings do. The primary concern in dive safety is always the correct gas mixture in the tank to avoid life-threatening mistakes.