Rebreather Explorer

Rebreather Types is about efficiency, NOT injection methods even one type of unit may have several ways of injecting gases to it whic adds to the confusion. Traditionally divers need to catalog units in order to asses risk and therefore injection may play a big role, but a Rebreather Type is directly proportional to it's gas efficiency.

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Constant PO2 is a reminiscense of the efforts of early RB technology to proof advantageous to OC diving, however at the technical level is contraproductive and dangerous.

Traditional theory mixes between two gases with a possible big gap between them, usually one of the is pure O2 100%% which beyond traditional recreational limits is potentially a fatality situation.

On the contrary the gases been mixed should have less %% differences to avoid hipoxia and hiperoxia, and should be exchangable by diver during the dive as need. Adding Helium to reduce density and increased narcotic effects.

CCR technology independently of injection method can or cannot be dive using Constant PO2, but what are the advantages and disadvantages ?

The IDREO Oxygen Consumtion Rate / Volume Drop Test allows the rebreather diver to identify the partial reduction of rebreather gas volume due to diver metabolism, in fact the inner gas volume in rebreather can be completely depleated as in not possible to creata gas flow and countelrung movement.

The time for the Voume Drop to happen is proportional to the Counterlung size, Diver metabolism and Dive activity intensity following a complete gas injection stoppage inside the unit. Such as running out of gas.

The Volume Drop test bring two keypoints to consideration:

• One is that in any case the gas inside unit must be of adequate levels when completely depleating the Volume, so we will obtain valuable information to e able to know the Minimum Operating Depths to be using each mix as applied to a particular type of Rebreather unit. In any case avoiding Hipoxia .
• Exact time of reaction upon a gas supply failure or switch.

Because performing a Volume Drop Test with low O2 content Mixes can lead to Hipoxia, this test should be perform in shallow water with O2, which when quantify for also allows to understand Oxygen Consumption Rate, as diver consumes al O2 thru metabolization, reducing the Volume in a period of time and therefore allowing a quite accurate stimtion of diver O2 Consumtion Rate for giving conditions, rest, swimming or working.

The Partial Pressure of O2 Consumption Rate test, PO2CR test, equipes the Rebreather Diver with the information need to complement minimum operating depth as well as performing the IDREO Gas Cycles.

IDREO CCR Gas Cycles is the amount of time mixes are usable without assistance of O2 rich mixes injection to control PO2 levels, this will be applied everytime an O2 rich injection gas in CCR rebreather fails and/or PO2 levels are intentionally kept low to avoid CNS% count.

To notice that single Gas Operated Rebreathers perform Gas supply switches to stay in the breathable ranges between the MINIMUM & MAXIMUM Operating Depths, ideally to allow safe Gas Cycles even after complete Volume Drop. To notice that OC do just that however there is total Volume Drop and total injection every breath.

The MAV Manual Adition Valve injects gas in a RB unit by diver action of pressing a button, MAV are usually use to aid PO2 Drop and connected to O2 Rich Gas.

The injection must be before the analysis of the MIX, in order to have proper readings, is extremely dangerous to inject gases after the analysis.

If MAV is not working, perform a Flow Check from bottle to QC6 or viceversa, but in one direction verifying QC6 is connected and bottle is open.

While RB Flooding is a possibility when Rebreather Diving, partial operation maybe possible but discourage as is the main reason why Divers and Explorers carry Bailout gas.

Responsible manufacturers will perform complete flooding test before releasing any product in order to identify the best way to clear units from water intrusion as well as buoyancy characteristics.

Using water weight and fluidity combined with gravity you can efficiently clear partial flooding of breathing hoses into CL, furthermore units with canister OPV can be completely cleared even after a complete flooding.

IDREO REBREATHER CONFIGURATION philosohpy is build upon simplicity & consistency among all platforms, the goal is to dive all units with the exact same way of operation, independently of RB Types and/or mounting capabilities, while reducing diver task loading.

The obvious advantages are compatibility among divers and equipment, but extend to gas standardization and decompression mangement.

Sidemount Configuration is been available since the 1960's bu mostly taken advantage by eager Cave Divers, lately has become aparent to most recreational Divers and its great. Here are some simple configuration guidance as is not really that hard to figure out, however the planning in order to acomplish other than recreational open water needs to be taken seriously to avoid confusing redundancy needs resulting in extremely complicating a other way simple system.

An efficient and Safe Advanced Gas Bottle Switch differs from a Basic Bottle Gas switch as the diver will be doing multiple switches upon descent, bottom and during deco as opposed to a single switch to perform a brief deco stop with a single bottle and therefore less chances of amking the wrong bottle switch.

Furthermore Advanced Gas Bottle Switch may include doing so while operating Rebreathers and while handelling several different bottles with different Gases, Rebreather and DPV.

The gas Valve Drill hep create strength, flexibility and muscle memory in order to operate your valves while diving.

A systematic valve failure procedure will help you understand how to manipulate your tank manifold in a rebreather configuration, thru a simple elimination process, following the most used moving parts in the gas source system you can identified where is the leak coming from and minimized the gas loss.

A basic Pre-dive Check list will help your to be organize and not forget any step while assuring the proper configuration, adequate operation and overall integrity/functionality of your Rebreather prior to get in the water.

Side Mount Rebreather Diving is about making diver "Thinner" but simultaneously making it "Widder" is suitable for bedding planes but also maybe more convenient in some diving activities as far to reach dive sites such as sumps.

In fact its convenience and valve monitoring have make it a popular OC activity, however taking it to RB Technology is even lighter !

Side Mount Rebreather Diving is also a great way to increase redundancy in challenging Dives.

When discussing Bailout we are talking as the back up plan to get out of trouble, in diving the worst possible scenario is sharing gas from the furthest point of penetration.

Proper Bailout is enough quantity of gas to make a OOG scenario work from furthest penetration point back to the surface, divers require to be able to make acurate estimations of gas need, plan adequate redundancy for further failures and be able to handle the bailout carrying options such as double tanks, stages bottles, deco bottles, multiple scooters and DPV's maybe be need to make the Bailout feasible.

Variations of Bailout are Minimim Reserve and Rock Bottom with basically same deifinition but applicable to specific situations such as a direct ascent to surface vs tunnel trael prior the ascent.

NDL stand for NO DECOMPRESSION LIMITS, but thruth is there is not such a thing as we relay on ascent speed, 10 MT / 30 FT per minute or if you wish 20 second stops each 3MT / 10 FT so to explain.

NDSL may be more accurate and stands for No Decompression Stop Limits, which are the minimum times a diver can stay underwater at a given depth before having to perform actual decompression stops before surfacing, so pretty much a direct ascent to surface, as long as respecting a defined minimum ascent speed usually 10mt/30ft per minute.

NDSL Times varies with depth and therefore flexibility in figuring out the times is key in manging efficient and safe exposures.

IDREO offers an easy and accurate rule to "on the fly" been able to figure your NDSL, while at the same time build up the skill need to manage the flexibility exploration diving will require. Notice the plan dive is not always possible to know ahead of time or can change dramatically without expecting it while underwater.

In short 120 rule.

Standardized Hand Signals make extremely fast and accurate comunication while underwater, without having to Stop and write down what is going on in your wetnotes. Wetnotes are mostly used for Data gathering.

Repetitive task are best served by a specific set of Hand Signals, notice gloves or to slow or fast movements make create complications when aplying Hand Signals for communication.

Basic Dive Signals

Expert Divers use lights not only to look around but for efficient communication.

Light communications is both Active & Passive.

In this lecture we review Light Communications and Light Signals the goal is to understand them better to take the most advantage from using them.

All divers must be reasonably educated about Basic Diving Equipment function and operation as well as periodical maintenance.

The Basic Diving Equipment is Open Circuit and is a redundant (back up) version of the traditional Single Tank Diving, the extra components greatly increase diver task loading if not properly configured.

We should strive to bring only what we need for the dive, making sure we don't leave nothing we need behind but more important we are not dragging stuuf we don't need. Owning a piece of Basic Diving Equipment does not automatically means we have to take it.

DEF OW Sidemount configuration is solid foundation to explore the underwater realm, it's minimalistic approach allows the diver to efficently move underwater due to minimum drag.

This is the DEF Scuba Explorer main recommended configuration for Non Divers.

The DEF OW Sidemount configuration is based in a back plate with a solid one piece webbing strap.

You can test yourself in this Rebreather Explorer Test, all the important information a diver needs to know is included in this test make sure you have not miss anything !

Test available in various languages.

Notice : This test is to be printed and completed when you are joining IDREO Training.

Congratulations for completing this course !

In this course in order to become a Safe and Efficient Dive Explorer we review and strength the following course sections :

• Rebreather Diving

You have complete all lectures included in this course, you can verify by the green dot next to each lecture on the course dashboard.

Don't loose the chance to verify you got a hang of all basic information by testing yourself in the written examination.

If you have any questions attend the live webminar, place them on the questions board or contact us at info@idreo.org

We sincerely wish you great Underwater Adventures !