TS EN ISO 24805/A11

TS EN ISO 24805/A11 is an amendment document for the competency framework used in recreational diving services, focused on rebreather diver training. It addresses the skills a diver must develop for dives that include mandatory decompression stops, and how those skills are assessed in training.

According to the scope, the document specifies requirements for training programmes that prepare divers to use a rebreather to 40 m with a nitrox breathing mixture or to 45 m with a trimix breathing mixture. It also sets out the evaluation criteria for those competencies and places the training requirements alongside the general provisions for recreational diving services in ISO 24803.

Technical meaning of rebreather, nitrox and trimix

A rebreather recycles part of the breathing gas, so training must cover gas management, monitoring and planning in a way that differs from open-circuit scuba. Nitrox is an oxygen-enriched breathing mixture, while trimix combines oxygen, nitrogen and helium. For deeper diving, trimix is used because it changes the breathing-gas characteristics and the operational approach to depth-related exposure and decompression planning.

What this document means in practice

• It distinguishes the depth range and breathing mixture used in the training programme.
• It defines competency targets for dives requiring mandatory decompression stops.
• It includes criteria for evaluating those competencies.
• It works together with the general requirements for recreational diving services rather than replacing them.