EXTENDED DECOMPRESSION: TRAINING WHERE HELIUM IS NOT AN OPTION
There are many great dive sites around the world where the logistics simply make trimix diving impractical. Helium is either unavailable or priced out of reach unless your net worth includes ownership of a 72-metre private yacht. One option is to use compressed air as your bottom gas rather than missing out on the adventure. RAID’s Extended Decompression program (with a maximum depth limit of 55 metres) will deliver the training and help build the experience, proper techniques, equipment choices, and potential hazards of deep air diving. This course is equipment intensive and challenges students (and instructors) to manage up to three decompression gases (nitrox to pure oxygen) during a controlled staged ascent.
Topics covered in this RAID program include a history of deep air diving, solutions for dive planning deep dives, the physiological stresses of deep air diving, hypoxia, oxygen toxicity, the vagaries of inert gas narcosis, hyperthermia, and decompression stress.
Dive plans at this level will include detailed gas planning for exploration at considerable depth, resulting in lengthy decompression. In this course, you will recommend gas choices tailored to the mission and reinforce the need for precise oxygen management. Gaduates from this program have a solid understanding of deep diving without the aid of trimix and will be drilled in complex equipment management and in carrying multiple stages that require detailed gas-switching procedures. They will demonstrate exceptional skills under difficult conditions.
Contact your local RAID Dive Centre for details.
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OVERVIEW OF COURSE STANDARDS
Purpose:
This course is designed to train Students to safely: • Dive to a maximum depth of 55 metres / 180 feet. • Use air, nitrox, oxygen. • Complete planned decompression. o Divers must have sufficient volume to complete a safe ascent, including the required decompression plus one-third reserve to share gas with a buddy. • Use a higher oxygen content nitrox (up to 100% oxygen) in up to 3 separate stage cylinders to optimize decompression dive times. o Bottom gas may have a maximum PO2 of 1.4 at depth. o Decompression gas may have a maximum PO2 of 1.6 at depth.
Student Prerequisites:
A Student taking this course must: • Be a minimum of 18 years old. • Be certified as RAID Advanced Decompression or Limited Trimix Decompression. • Be certified as RAID Master Rescue (or equivalent). • Have a minimum of 65 logged hours underwater or 100 dives using open circuit. • Have logged at least 20 dives between 30 – 40 metres /100 – 130 feet. • Have logged at least 10 decompression dives. • Complete the registration process, including all mandatory online documentation. RAID Technical Diver Standards V 60.0 | 17 • Submit current First Aid & CPR training and Oxygen Administration certificates.• Be certified as a RAID Sidemount or RAID Twinset divers if doing the course using either configuration.
Course Requirements:
To earn certification, the Student must fulfill the following requirements: • Complete the online academic modules, quizzes, and exam. o Management. o Confined water. o Open Water. • Complete all the skill requirements as outlined in the manuals for in-water training: o Pre-dive safety checks. o Buoyancy check. o Stage remove and replace on the surface. o Descents. o Buoyancy and trim. o Long hose recovery. o Frog kick. o Back fin. o Modified flutter kick. o Helicopter turn. o SAC rate calculations. o Stage remove and replace underwater. o Gas sharing stationary. o Gas sharing swim. o Gas sharing swimming ascent. o Back-up mask deployment. o Gas switch protocols. o Shutdown drills. o SMB deployment. o Rescue ascent. o Ascent with simulated failed decompression plan.
Who can conduct the course (minimum level Instructor for the Course):
The RAID Professional conducting this course must be at least a RAID Extended Decompression Instructor, Normoxic Trimix Instructor, or above. Instructors must hold the Instructor rating for the system they are teaching, twinset or sidemount.
Supervision:
A certified RAID Extended Decompression Instructor is defined as an in-status RAID Twinset Extended Decompression Instructor or RAID Sidemount Extended Decompression Instructor or higher. All training must be conducted by any Instructor listed above. The Instructor must be physically present and directly supervise all training segments. A Certified Assistant must be a RAID Divemaster or higher, certified in Extended Decompression or higher. NOTE: Instructors certified as OC Extended Decompression Instructors and CCR Normoxic Instructors, or higher, may use the rebreather for which they are certified to teach while conducting Decompression diver training dives, provided that skills pertinent to open-circuit diving are not demonstrated. This standard only applies to open water dives.
Instructor/Student Ratios:
The maximum ratios are: Confined Water • A maximum of 4 Students: 1 Instructor. Open Water • A maximum of 3 Students: 1 Instructor. • A maximum of 4 Students: 1 Instructor with a Certified Assistant. NOTE: It is highly recommended that a certified RAID Assistant be utilized. VII. Depth Limitations During Training The training dive depth limits for individual dives are outlined in the training materials. Overall, training dives must not exceed a maximum depth of 5 metres/ 15 feet in confined water and 55 metres / 180 feet in open water. At least two dives should be deeper than 45 metres / 145 feet and one dive deeper than 50 metres / 165 feet. Training dives should be planned and executed using conservative decompression parameters. For the safety of the student and instructor, RAID recommends that during training, the most conservative settings be applied.
Equipment Requirements:
• Twinset or sidemount cylinder setup. • Technical regulator setup fitted with a long hose, including a piston clip. • One low-pressure (LP) inflator hose for BCD and dry suit (if appropriate). LP connectors must be interchangeable. • One backup regulator with standard hose fitted with neck bungee. RAID Technical Diver Standards V 60.0 | 19 • One SPG with a piston clip. OPEN CIRCUIT TECHNICAL PROGRAM STANDARDS • Stage cylinders holding a suitable gas volume for planned dives. • Stage cylinder rigging kit. • Cylinder marking for MOD, Diver Name and Mix (labelled as per RAID cylinder marking standards). • Suitable DIN regulator with SPG on a short HP hose. • Wing, plate and harness. • Redundant buoyancy. • Personal dive computer. • Backup computer or depth dive timer. • Wetnotes or wrist slate or finger slate. • Primary SMB. • Emergency SMB. • 1 x reels or spools with adequate line length for the dive depth. • 2 x cutting devices. • Backup Mask. • Light where appropriate. • Smartphone, tablet or laptop with decompression software. • Access to a nitrox or mixed gas analyzer.
In Water Training:
Each Student must complete these requirements. • Minimum of 1 confined water dive with no minimum time requirement. • Minimum of 4 open water dives with at least 3 hours of underwater training. X. Certification The Extended Decompression certification entitles the holder to dive with a certified dive buddy to a maximum depth of 55 metres / 180 feet in conditions similar to or better than those experienced during training, using air or nitrox with optimized decompression. Certification will be awarded in the diving system used for training.
Special standards for this certification:
Students certified as Sidemount Extended Decompression may crossover to Twinset Extended Decompression by completing 1 confined water session and 2 open water dives. • Students certified as Twinset Extended Decompression may crossover to Sidemount Extended Decompression by completing 1 confined water session and 2 open water dives.