Accelerated Decompression Procedures

Course Content

The syllabus combines theoretical understanding with practical open water skills. While details may vary slightly by training centre, a typical Accelerated Decompression Procedures course includes:

Theory Modules

• Decompression Theory: Understanding inert gas loading, off-gassing, and how acceleration with higher oxygen mixes reduces required decompression time.
• Gas Physiology: Effects of elevated PO₂, oxygen toxicity management, and CNS and pulmonary oxygen exposure limits.
• Dive Planning: Using decompression software and tables to plan staged dives with accelerated decompression, including contingency planning and gas calculations.
• Equipment Configuration: Setup and use of stage cylinders, regulator marking, decompression gas identification, and streamlining for safety and efficiency.
• Emergency Procedures: Handling out-of-gas scenarios, missed decompression stops, and gas switch errors.

In-Water Skills

• Stage Gas Deployment: Carrying and deploying at least one decompression gas cylinder, including secure attachment and removal underwater.
• Gas Switching: Safe and efficient execution of gas switches at planned stops using correct verification procedures.
• Buoyancy Control: Precise buoyancy and trim throughout the dive, particularly during decompression stops and gas switches.
• Ascent and Stop Management: Conducting controlled ascents with staged decompression stops, managing stop durations and depths accurately.
• Problem Solving: Simulated failures such as gas loss, equipment malfunction, or incorrect gas switch, followed by appropriate emergency responses.

Expect to complete at least two open water dives with staged decompression using EAN50 or Oxygen. Some centres may offer more depending on student performance and local conditions. All dives are conducted within no deeper than 40 m / 130 ft, unless combined with further technical training.

As always, course content may vary slightly by training centre. On adventuro, you can compare hundreds of diving courses, trips and gear rentals to find the right fit for your diving journey.

Completing the Accelerated Decompression Procedures course enables divers to conduct staged decompression dives using gas mixes with higher oxygen content than bottom gas – typically up to 100% Oxygen. This can significantly reduce decompression time when used correctly and within planned limits. You'll be trained to carry and manage at least one additional decompression gas safely, perform gas switches at depth, and follow multi-level ascent profiles with confidence.

This course forms part of the foundation of technical diving and opens the door to deeper dives, extended bottom times, and more advanced qualifications such as Trimix or Extended Range Diver. It’s ideal for divers looking to explore deeper wrecks, walls, or technical environments where decompression obligations are unavoidable. Most importantly, it reinforces risk assessment strategies and redundancy practices essential for safe diving in more complex situations. After certification, you’ll be qualified to join guided technical dives or continue progressing along the technical diving pathway.

• You must be at least 18 years old.
• You must be a certified decompression diver (such as BSAC Sports Diver, PSAI Advanced Open Water or equivalent).
• You must have a minimum of 50 logged dives, with experience in dives deeper than 30 m / 100 ft recommended.
• You should hold a Nitrox certification (e.g. BSAC Nitrox Diver, PSAI Nitrox Diver or equivalent).
• You need to be medically fit for diving and complete a medical questionnaire or provide a doctor’s approval.
• Comfort with buoyancy control and gas management under task loading is essential.

The Accelerated Decompression Procedures course typically takes 2–3 days to complete. This includes classroom theory sessions, dive planning exercises, and at least two open water dives. Some training centres may offer this course as part of a modular technical diving pathway, so timescales may vary slightly.

Assessment for the Accelerated Decompression Procedures course, whether through BSAC or PSAI, is practical and performance-based. Divers are evaluated on their ability to plan and execute dives requiring staged decompression, using air, nitrox, and oxygen within safe operational limits. You'll demonstrate skills such as accurate gas-switching, awareness of decompression obligations, and managing emergency scenarios. Expect dive planning exercises, in-water drills, and scenario-based assessments under instructor supervision. Some theory exams or knowledge reviews may also be included, depending on the training centre. Adventuro lists centres that provide expert instruction and supportive coaching if you need extra time to master the skills.