This top-level advanced mixed gas course is aimed at divers who wish to use the Poseidon Se7en eCCR for mixed gas dives. The goal of the course is to train participants in the benefits, risks, and correct procedures for diving with mixed gas on the Poseidon Se7en eCCR. The course includes dives to a maximum depth of 100 meters using trimix with an oxygen content of 16% or less.
Participants will learn to:
- Pre-dive and preperation checks
- Demonstrate planning procedures before the dive, System identification and redundancy planning, Selection of conservatism (gradient factors), Assessing thermal limitations, Planning emergency decompression
- Rescue and ascent procedures, Managing gas loss scenarios, Communication using hand signals or audible signals, Identifying damaged hoses / loops, Flooded scrubber canister / CO2 breakthrough, Dealing with oxygen value deviations, Flooded breathing hose / loop, Electronics and battery failure, Loss of buoyancy
- Bubble check / linearity test at 3–6 meters depth, Electronic PPO2 monitoring and setpoint adjustment, MAV control, Operating head-up display and dive computers, Monitoring the dive buddy throughout the dive, Monitoring the remaining life of the CO2 absorbent
- Removing, replacing, and clearing the mask, Removing, switching, and clearing the backup mask, Using lift bags / SMBs and spool/reel, Adhering to dive limit, Conducting safety stops, Consistent management of loop breathing volume, Behavior in mixed diving teams (OC and eCCR), Switching to bailout and safe OC ascent
- At the surface: Establishing positive buoyancy with the BCD and closing the mouthpiece, Demonstrating manual inflation of the BCD at the surface
- Buoyancy control by maintaining a depth within ±1 meter for at least 90 seconds, Demonstrating proper use of oxygen controls including confirmation of automatic setpoint changes, Demonstrating proper operation of the BOV, Removing water from the breathing hoses, Maintaining optimal loop volume, Maintaining neutral buoyancy while swimming in a horizontal position, Behavior during depth changes: manual gas addition (oxygen, diluent), Performing a diluent flush, Performing simulated decompression stops, Deploying a surface marker buoy (SMB), Controlled ascent with contact to the buddy and correct ascent rate
- Swimming with bailout/decompression cylinder, Removing and reattaching the bailout/deco cylinder while maintaining buoyancy, Deploying SMB / lift bag alone and as a team, Reaction to gas loss from the first stage, pressure gauge, or primary regulator on
- bailout/deco cylinder, Reaction to simulated free-flowing deco regulator, Gas sharing with deco gas between divers for 1 minute, Oxygen rebreather mode at depths <6 meters, Bailout scenario at depth with decompression obligation in open circuit
- Correct placement of the stage at the surface, Exiting the water using an environmentally suitable technique, Proper care and disassembly of the rebreather, Cleaning and disinfection of the device, Flushing the device with freshwater, Rinse and disinfect mouthpiece/BOV, counterlung, hoses, and scrubber sponge, Cleaning and disinfecting the device, Inspecting components of the device, General maintenance of the unit, Removing and replacing sensors if necessary, Charging batteries
Prerequisites
- Certification: The participant must be certified as a Poseidon Se7en eCCR Mixed Gas Diver in accordance with ISO 24805 or an equivalent standard, nd must also hold a Trimix Diver certification from an ISO-compliant recognized organization.
- Minimum age: 18 years
- Diving experience: The participant must have at least 1 year of experience diving with the Poseidon Se7en eCCR at the mixed gas level. Verified documentation of at least 30 logged mixed gas dives on the Poseidon Se7en eCCR is required, with at least 25 of those dives conducted to depths greater than 50 meters using trimix.
- Additional requirements: A valid certificate of first aid and oxygen provider training is required, if mandated by local regulations.
Course Structure
Poseidon Training permits instructors to flexibly adapt the course to the number of participants, their skills, and their level of knowledge. This allows for an individualized design of the curriculum to optimally address different learning levels.
Theoretical requirements: For the theoretical part, the Poseidon Training e-learning for the Poseidon Se7en eCCR must be used. To pass the final test, a score of at least 80% of the maximum points is required. All incorrectly answered questions must then be reviewed together with the participant to ensure complete understanding. If the e-learning is not available in the participant’s language, the english version must be used.
Course duration: The course should extend over a minimum of 5 days. This ensures sufficient time to adequately convey and reinforce both theoretical content and practical exercises.
Theory and equipment workshop: At least 6 hours of theoretical instruction are required, complemented by a 4-hour practical workshop on maintenance. In this, participants gain solid insights into the maintenance of diving equipment and the Poseidon Se7en. Part of this theoretical training is conducted through the e-learning program from Poseidon Training for the Poseidon Se7en eCCR.
Preparatory measures before pool or confined open water (swimming pool–like conditions): Before the first dive, equipment configuration must be carried out. This includes individual adjustments, proper setup, and training in the safe handling of the Poseidon Se7en eCCR equipment.
Pool or confined water (swimming pool–like conditions): At least 1 dive with a total duration of at least 60 minutes are required, conducted at a maximum depth of 9 meters. Fundamental skills are to be reinforced under controlled and safe conditions. All new skills must be demonstrated by the instructor in confined open water, and participants must master all skills in this environment before performing them in open water.
Preparatory measures before open water dives: Before the actual open water dives begin, a fully equipped eCCR diver must be towed for 50 meters at the surface. This serves to check the equipment configuration and the diver’s physical performance under realistic conditions.
Open water – Introduction and preparation: 1 configuration dive with air as diluent for equipment adjustment and safety training must be conducted before the start of the mixed gas phase. The maximum depth is 40 meters, the minimum duration is 60 minutes.
Open water – Scope and structure of training dives: At least 4 open water dives with a total dive time of no less than 240 minutes must be completed in order to develop and consolidate practical skills.
Open water – Dive depth during open water dives: At least 2 open water dives must be conducted to depths of at least 60 meters each. In addition, 1 further dive must reach a target depth between 75 and 90 meters.
Theory Sessions:
- Properties of helium and the use of trimix
- Challenges in the use of oxygen, helium, and nitrogen
- Gas physiology for rebreather diving with trimix
- Medicine for rebreather diving with trimix
- Technology / configuration
- Dive checks
- Gas management and bailout strategy
- Diving practice
- TG calculation and planning for normoxic trimix dives (MOD, CNS, OTU, EAD, END)
- Determination of decompression data
- History and development of rebreathers
- OC/CC comparison – advantages and disadvantages
- Practical mechanics of the system
- Development and maintenance of electronic systems
- Dive tables
- M28 dive computer
- Dive planning
- Procedures and protocols for emergencies
- Flooded loop
- Warnings, battery warnings, sensor warnings, and electronic failures
Training Sessions:
- Session 1 (Open water with maximum 15m diving depth)
- Flush the counter lungs, linearity test, bubble checks, maintaining buoyancy control
- Switch to the bailout regulator (bailout gas/stage). Controlled ascent to 6m
- At 6m, switch from bailout to CC
- Rescue exercise: Simulation of an unconscious eCCR diver, Bringing the diver to the surface while maintaining buoyancy control, establishing a stable floating position there, and transporting to shore/boat
- Session 2 (Open water with a maximum diving depth of 30m)
- Planning of the dive with the Reef app.
- Flush the counter lungs, linearity test, bubble checks, maintaining buoyancy control
- Bailout scenario: Switch from Se7en to stage 1 (bailout gas 1 – depth gas), switch the M28 to OC mode; after approx. 1 min switch to stage 2 (bailout gas 2 – travel gas), Ascend to 21m and switch to stage 3 (bailout gas 3 – deco gas), Ascend to 6m at a maximum of 3m/min and switch to stage 4 (bailout gas 4 – oxygen), With each gas switch, set the M28 to the corresponding gas in OC mode
- Switch again from stage 4 (bailout gas 4 – oxygen) back to the Se7en and set the electronics back to CC mode
- Session 3 (Open water with a maximum diving depth of 30m)
- Flush the counter lungs, linearity test, bubble checks, maintaining buoyancy control
- Detach the travel gas stage and attach it to the reel/spool, then swim approx. 15m away, Detach the deco gas and oxygen stage secured to the leash, attach both to the reel/spool, then swim an additional 15m away, Remove mask and swim back along the deployed leash without mask, put mask back on and clear it, Detach 3rd and 2nd stage from the leash at the reel/spool and re-attach them; while rewinding the reel/spool, swim back toward the 1st stage, Detach 1st stage from the reel/spool, re-attach the stage and stow the reel/spool,
- Switch from CC mode to bailout gas 1 (bailout gas 1 – depth gas) with the exercise “stage regulator free flows” for at least 1 min, switch the M28 to OC mode, then switch back to the Se7en CC mode and reset the M28 to CC
- At the end of the dive, deploy an SMB at 6m
- Then perform a controlled ascent to the surface at 1m/min
- Session 4 (Open water with a maximum depth of 30m)
- Flush the counter lungs, linearity test, bubble checks, maintaining buoyancy control
- Change the setpoint from 1.3bar to 0.7bar and perform a controlled ascent to 15m while manually maintaining a PPO2 of 1.1bar
- At 6m, manually maintain a PPO2 of 1.5bar and deploy an SMB
- Then perform a controlled ascent to the surface at 1m/min
- Session 5 (Open water with maximum diving depth of 40m)
- Flush the counter lungs, linearity test, bubble checks, maintaining buoyancy control
- Switch to bailout gas and set the M28 to OC and the bailout gas
- Speed-controlled ascent to 30m and switch to travel gas. Set the M28 to travel gas
- Speed-controlled ascent to 21m and switch to deco gas
- Controlled ascent with simulated stops at: 18m, 15m, 12m, 9m, 6m
- At 6m, deploy SMB and then switch to Se7en CC mode, manually maintain a PPO2 of 1.5bar (oxygen rebreather) for 1 min, and reset the M28 to rebreather mode
- Then perform a controlled ascent to the surface at 1m/min
- Session 6 (Practice dive in open water with a maximum depth of 45m and a maximum bottom time of 15 minutes)
- Flush the counter lungs, linearity test, bubble checks, maintaining buoyancy control
- After 15 minutes, ascent at a maximum ascent rate of 10m/min
- At 30m, set the setpoint to 1.2bar
- Deep stops and deco stops as indicated by the M28
- At 20m, set the upper setpoint to 1.0 bar and manually maintain a PPO2 of 1.2bar
- At 15m, deploy SMB
- At 6m, set the setpoint to 0.7bar and manually maintain a PPO2 of 1.3bar
- Controlled ascent to the surface at 1m/min
- Deploy SMB and then ascend to the surface at 1m/min
- Session 7 (Practice dive in open water with maximum 60m diving depth and maximum 20 minutes bottom time)
- Flush the counter lungs, linearity test, bubble checks, maintaining buoyancy control
- After 20 minutes, ascent while observing deep stops and deco stops as indicated by the M28
- At 6m, set the setpoint to 0.7bar and manually maintain a PPO
- Deploy SMB and perform a controlled ascent to the surface at 1m/min
- Session 8 (Practice dive in open water with maximum dive depth of 80m, 15min. bottom time)
- Flush the counter lungs, linearity test, bubble checks, maintaining buoyancy control
- After 15 minutes, ascent at 3m/min
- Deep stops and deco stops as indicated by the M28
- At 6m, deploy SMB and perform a controlled ascent to the surface at 1m/min
After the Course
After successful completion of the course, graduates are authorized to conduct technical dives with the Poseidon Se7en eCCR to depths of up to 100 meters.
The use of mixed gas diluents with less than 16% oxygen is permitted. Dives must be carried out under conditions comparable to those encountered during training – including depth, visibility, environmental factors, temperature, current, and technical equipment such as stages, buoys, and gas management.
Refresher requirement in case of inactivity: A refresher course is mandatory after an eCCR inactivity period of more than 6 months. If a certified diver has not conducted any eCCR dives during this period, an appropriate course must be completed before resuming technical dives.