What aspect of diving does an EANx course primarily focus on?

The primary focus of an Enriched Air Nitrox (EANx) course is learning to manage and use enriched air safely in various diving scenarios. EANx is a specific blend of gases that typically has a higher percentage of oxygen than regular air. By utilizing this enriched air, divers can extend their bottom time at certain depths and reduce the risk of nitrogen narcosis.

The course provides essential training on how to analyze the oxygen content in a dive tank, plan dives taking into account the specific oxygen percentage in the gas mixture, and understand the depths at which enriched air can be safely used. This knowledge helps divers avoid potential risks associated with high oxygen levels, such as oxygen toxicity, and enhances their overall diving experience by allowing for more efficient dive planning and execution.

The other options, while related to diving, do not address the specific training or objectives of an EANx course. Understanding the history of diving, practicing free diving techniques, and exploring deep-sea ecosystems are important in the broader context of diving education but do not pertain to the specialized training that enriched air nitrox courses provide.