ISO 24804:2022

Overview

ISO 24804:2022 - Recreational diving services - Requirements for rebreather diver training - No-decompression diving defines minimum rebreather diver training requirements for recreational divers using rebreathers with a nitrox breathing gas. The standard covers training programmes that prepare divers to conduct no-decompression dives to a maximum depth of 30 m, and it specifies evaluation criteria for the required competencies. Training providers must meet these requirements in addition to the general service provisions of ISO 24803.

Key topics and technical requirements

• Scope and competencies
  • Competency outcomes for safe operation of rebreathers on no-decompression nitrox dives to 30 m.
  • Evaluation criteria for knowledge and practical skills.
• Theoretical knowledge areas
  • Rebreather basics and types (e.g., closed-circuit and semiclosed-circuit concepts).
  • Function of rebreather components, set-points and PO2 (partial pressure of oxygen).
  • Breathing loop dynamics, respiratory minute volume (RMV), gas supply and CO2-absorbent duration.
  • Hazards: CO-related issues, hypercapnia, hypoxia, hyperoxia.
  • Pre-water-entry checks, dive planning and no-decompression dive conduct, buddy system.
  • Rebreather maintenance and continuing skills/knowledge retention.
• Practical skills
  • Pre-dive procedures, assembly and checks, in-water procedures, emergency responses and post-dive procedures.
  • Hands-on training parameters and instructor responsibilities.
• Equipment and evaluation
  • Requirements for training equipment and materials.
  • Skill evaluation protocols for closed-circuit rebreathers (CCR) and semiclosed-circuit rebreathers (SCR).
  • Proof of qualification and documentation expectations.

Applications - who uses ISO 24804

• Diving training organisations designing or auditing rebreather courses.
• Dive instructors and certification agencies needing standardized competency checklists.
• Dive centre operators and safety managers implementing compliant training programmes.
• Regulators and tourism bodies setting minimum training requirements for recreational rebreather use.
• Equipment manufacturers and technical authors referencing training content or safety-related user instructions.

Related standards

• ISO 24803 - Recreational diving service provider requirements (general).
• ISO 11107 - Training programmes for enriched air nitrox (EAN).
• ISO 24801-2 - Level 2 autonomous diver training requirements.
• ISO 24802-2 - Scuba instructor level 2 requirements.

ISO 24804 is essential for organizations and professionals who train, certify or manage recreational rebreather divers and who need a clear, safety-focused baseline for no-decompression nitrox rebreather programmes.