Is Trimix Recreational?

Recreational Trimix or not? Why Helitrox is NOT the best choice for average Recreational Divers

BACKGROUND: This past weekend I had a customer in for air fills who was told me he was taking a “recreational trimix” course. When asked about why he was taking it he mentioned that it would be nice diving a shipwreck like the Forest City up in Tobermory (145′ max depth) without getting narked, but the Nitrogen narcosis is a common problem with divers exceeding a depth of 30msw/100fsw because the nitrogen pressure breathed at this depth can cause a mental impairment to the diver similar to alcoholic intoxication or being high on drugs.  

The affect of the narcosis varies based on the divers comfort in the water and their ability to handle certain stressors.  Some divers feel a sense of euphoria, while others feel fear and hear their hearts thumping loudly as it echo’s like a bass drum through their entire body.

Diving the wreck of the Forest City in Tobermory is no longer a recreational dive once you pass the 130ft depth.

I wanted to touch on a few things, namely why Recreational Divers Should Train Up.

Helitrox  is essentially Nitrox (elevated partial pressure of oxygen and decreased partial pressure of nitrogen) with Helium in it, hence the name being used publicly since 2005 as a recreational and technical diving specialty. Since 2001 we’ve been using Helitrox successfully for bottom mixes at depth as well as deco mixes to improve the effective elimination of inert gas in colder water.

By utilizing Helium as part of our breathing mixes, we have a lighter gas to breath that dilutes both the oxygen and the nitrogen to extend our depth range, while maintaining a safer narcotic depth that reduces our absorption of carbon dioxide, which is a contributing factor to nitrogen narcosis.  Helium is a non-narcotic molecule.

air/nitrox, which I’ve been guilty of in the past. Having dove this wreck while teaching a deco course and

getting more narked than I’d ever been on deep air, I vowed never to dive anything in the 130 foot range or

deeper, on air again because the average diver’s stops encoding the wreck as efficiently. Diving the Forest

City on Trimix was like going from a black and white television picture with rabbit ears to full HD Blue

Ray as the picture quality was flawless and I was able to remember the dive as clearly and vividly as

diver and his team lack the right equipment or skills to safely engage in this type of diving, which made me

look at the in’s and out’s of trimix diving as a recreational diver.

Trimix is not so recreational, nor is it the best choice for the

“average recreational diver.”

HELITROX

We’ve been teaching Helitrox which is a hyperoxic

combination of Oxygen (+21%) and combination of

Helium typically 13-17% with the balance being Nitrogen.

proper term for it is Helitrox, which we have taught

ADVANTAGES

Diving trimix is amazing as a diver. You virtually

eliminate the narcosis because you’re decreasing the

narcotic potency of the air or regular nitrox with an

Imagine seeing this wreck this clear: Above are two

photos from the point where the wreck of the Forest City

stops being recreational and enters the technical diving

realm. The top photo shows the stairs that most divers barely recall are ever there after diving it deep on

not a recreational dive at the

We went as far as to start testing effects of narcosis and benefits of trimix on a trimix course one day when we took our students to our local wreck in Lake Ontario, the Tiller in 95-110 foot range with divers who

incredible asset to them and that indeed they were suffering some previous impairments even at depths of

100-110 feet.
It’s experiences like the above two that really drove home the benefits of trimix in recreational diving to

me, but that comes at a huge time investment and a serious financial investment to the diver which the

Some training agencies such as IANTD, GUE, NAUI and UTD have been offering “recreational trimix” but

of the them, only the last 3 have implemented a series of courses that support the configuration and skills

These are examples of agencies who are the exception rather than the norm for properly training

recreational divers to use recreational trimix.

(Doing It Right) diving with the proper equipment configuration, knowledge, skill and technique, I would not recommend recreational trimix, especially if you are a

traditional diver trained in a traditional equipment configuration and skill set.
not for your standard run of the mill every day

possible. This is where trimix is great, but due do the depth of this wreck

stern section.

had dove this ship dozens of times. Despite all the diving on it the nitrogen numbed their ability to encode

certain features and artifacts on the wreck itself until they dove it with me on Trimix.

average recreational advanced open water diver trained by a traditional dive store (that promotes very

traditional equipment configurations and diving practices) will not fully understand.

required to mentally and physically prepare their divers for the disciplines of diving with helium based

mixes structuring 3-4 courses in a row that build on the previous depth, skills and mixes the divers breathe.

There are many potential problems ahead for those dive stores who are promoting recreational diving and

helium together. Unless you are a modern and active diver who has embraced modern techniques from

the field of modern day

Following are some of the reasons why trimix is

COST

Cave or DIR

recreational divers.

Helium is more expensive than oxygen, argon or other compressed gasses used for scuba diving.

While most stores can fill nitrox at a fairly reasonable price, helium is usually more than double the cost of

oxygen in most dive stores and takes more time and requires more calculations to blend.

Are clients going to want to spend approximately $30.00 for a single aluminum 80 filled with a 26/17

Helitrox mix? What if you’re using double tanks? Now you’re doubling the cost of that 80 fill to $60.00. If

you have high capacity steel tanks you’re looking at an even higher cost for singles and doubles.

Bounce diving (swimming as fast as you can to your maximum depth) is also not recommended for

helium based mixes.

As a technical diver you would be able to easily spend 30 minutes (as a random bottom time but can easily be much longer) at a depth of 130 feet and your bottom gas cost for a pair of low pressure 85’s (which are

Qualifying yourself as a Technical Diver will be a far better investment for the diver looking to fully benefit from trimix (especially if that diver is already wearing double tanks or used to carrying a pony bottle). Why go half-way when you can go all in and get the most out of the mixes you want to breathe.

Your cost per minute of bottom time as a recreational diver diving to a depth of 130 feet where the No

Decompression Limit is only 5 minutes, is going to be roughly $6.00 per minute of bottom time if you

divide the cost of the fill by the maximum bottom time.

the tank size you would require for 30 mins at this depth) would be approximately $59.00 which is less

than $1.00/minute of bottom time.

If the average diver wants a higher octane mix like a 30/30 fill for a 110 foot to 120 foot dive, the cost for an

aluminum 80 would be approximately $40.00 versus $10-$15 for nitrox. NDL for a 110 foot dive on 30/30

is 11 mins.

If you are driving down to another dive store out of town just to save a couple dollars/tank to get filled on

standard compressed air, then the cost of recreational trimix is also not for you.

A friend of mine drew the analogy of fast-tracking to cave diving and the new cave graduate who decides

Hinkle

Divers need to put in their time and learn to deal with problems, shortcomings, equipment failures,

aborted dives and the unexpected incidents . They miss out on the learnings from each lesson.

Much like the divers that put the blinders on and only see the

because it’s 2400 feet in, they miss

learning valuable lessons and taking proper courses to further their skills and experiences.

Taking open water, advanced, doing a few dives here or there, buying a bunch of new gear to dive trimix

were to breath compressed air (21% oxygen/79% nitrogen) and even less no decompression time than if

you were to be breathing enriched air nitrox (+21% oxygen).

and then doing your first dive to 130′ on trimix is too much too soon, which is why the agencies give you

three to four courses to build on, above and beyond the basics.

NO DECOMPRESSION LIMITS

You’re dealing with a lighter gas when breathing helium, so while some would say it’s a great gas for

recreational diving we want you to understand that you will have LESS no decompression time than if you

1

Helium on-gasses into your body 2.65 times faster than nitrogen does. It also off-gasses faster, but requires

deeper stops and as a recreational diver, you are doing no stop recreational diving.

90 feet of depth breathing Helitrox 26%-30% oxygen and 13%-17% gives the diver a 20 minute no

decompression limit. Breathing air gives the diver 25 mins of no deco time according to the PADI

Recreational Dive Planner.

While trimix is more beneficial at depths deeper than 100′ when battling nitrogen narcosis you can see that the reason we view helium as a technical diving gas……because you do not have no decompression limits that are worthwhile in a mix capable of taking you to 130′.

best bundled as part of a technical diving course where divers are utilizing Advanced/Technical Nitrox, Decompression Techniques, Helitrox as a Technical Diver Level 1 combination course with the right equipment and the right divers to surround themselves with.

The majority of the divers who are willing to put in the time it takes to perfect the skills, create the disciplines and actually execute a dive on helium would benefit more from taking a technical diving class where they can then spend a much greater time at depth and wash out the inert gases on the ascent with

the trimix and then a switch at 20′ to pure oxygen for the final 2 deco stops at 20′ and 10′.

Why Take it twice? Taking rec trimix as a traditional recreational diver is a course you’re going to repeat again at the technical level which will offer a far more in depth, more academic and more skill intensive diver education. Why pay twice when you can do it right once?

The average recreational diver who wants to dip down near the stern of the Forest City will have run out

of no deco time getting down to it. If your goal is the stern of the Forest City or something in 130-140′

you’re pushing past recreational scuba and you are in fact exceeding your limits of training as a

recreational diver and are indeed doing a “technical dive”.

Lack of Equipment:

for a dive to 100, much less 130′ and often lack the equipment

to handle emergencies should problems arise on deeper dives.

All divers should be equipped using the same equipment

Gas Capacity: Most recreational open water divers wear a single aluminum 80 scuba cylinder which doesn’t give the diver much bottom time and offers no redundancy should the diver experience a free-flow, freeze-up, run out of air or have to share air with a diver.

In order for the average diver to spend 20 minutes of bottom time on air or nitrox at a depth of

Take your depth in atmospheres (in this case 100 divided by 33 feet/atmosphere +1) 4.03ata. Multiply your time (20 mins). Multiply your surface air consumption rate which I averaged at .75 cubic feet per minute.

Depth x Time x SCR or 4.03 x 20 x .75 = 60.45 required cubic feet. Diver then should multiply by 1.5 times

to get required air usage plus 1/3 left over for reserve. 60.45 x 1.5 = 90.67ft3 required

The average recreational diver is often poorly rigged with an

outdated equipment configuration that limits rescue response

and streamlining, but also ill-equipped and under gas capacity

configuration as a team revolving around the

DIR/NTEC/Hogarthian equipment configuration which promotes keeping it simple, streamlined and

uniformed across the board for each diver.

30msw/100fsw the diver would need a 91 cubic feet of air tank with gas reserve of 1/3 more than required

air for emergency.

Redundancy: Recreational divers diving deep need gas, lots of it for emergencies. You never know what

may happen down there. If you have to rescue someone, tow someone, donate air, etc., you will burn

more gas handling problems as the stress often elevates the divers breathing rate.

The average recreational should but rarely runs any sort of redundancy such as a pony bottle, high capacity

single tank with a dual outlet tank valve for 2 independent regulators to mount, sidemounted cylinders or

double tanks which all give the diver the ability to shut off and switch over to a completely redundant

regulator system in the event of a failure.

free ascent. Having not ever practiced a free ascend or ever spent time practicing with a lift bag or a reel

they deployed the unfamiliar equipment and ended up holding it on the surface because they didn’t know

how it went together or how to send it up from depth, so I motored over with the boat and made sure they were okay, didn’t need O2 or any sort of first aid and the 1 diver signed up for intro to tech and went technical after that, while the other diver chose not to dive to that level anymore.

are water divers do not want to spend $800 or so on a dive computer and don’t

If you don’t have a computer that tracks Helium, how do you know what your

No Deco limits are? This is where dive planning and dedication are so

Trimix Computers or Bottom Timers & Dive Plan: Trimix computers

more money than basic single gas nitrox computers, most recreational open

have the discipline or ability to stick to a pre-planned schedule where you write

out your dive plan and follow it down to the second while using a computer in

gauge mode or a digital bottom timer.

important.

sad state of computer dependant recreational diving it is rare for the average recreational open water diver

to pre-plan their dives and gas requirements, in addition to over and bail out plans incase decompression limits are violated, as most divers would just trust that dive computer to get them out of the water

underwater. If you don’t have backup depth/timing device you need to have exceptional team diving skills

as your dive buddies are your only other option.

is in your tanks after a remix the tanks should be drained. If you’re diving thirds that could be $50 in gas

you’re blowing off. It’s only $1000 approximately for an oxygen/helium analyzer.

safely…..it doesn’t always happen that way and when you have as short No Deco limits as you do with

Helitrox it’s more of a reality that deco comes up. Your brain is the best computer you can have

Helium analyzer: Do you have one? Does the dive shop? If not you’ll be dumping your mixes every

second fill as per the industry protocol, which states because of the uncertainties of just how much helium

Drysuit inflation bottle….Not just to keep you warm, they’re essential. Keep reading you’ll see why you

need a drysuit inflation system. $300-$400.

Pony bottle. What’s it filled with? Air? Nitrox? Helitrox? Hopefully it’s got helium in it. Much like the

drysuit bottle, keep reading to see why this is so important. If you need one for the course that could be

another $600-$1000 depending on the regulator you choose and the pressure gauge.

Additional Accessories: Canister light because things are darker at 130′ and you need something to allow you to communicate with your team effectively and secure your long hose. In addition to the canister light

Delrin essential tools as a recreational diver, but again most recreational open water divers do not know this

not a

married to each other as you need to be able to use that equipment any time any where with the utmost a safe option due to lack of familiarity

If you choose to take shortcuts in the required equipment, have homemade equipment, purchase low end or outdated equipment recreational trimix is not for you, advanced and technical diving is not for you, as diving to that level requires the best training and equipment possible.

divers are required to have at least 1 backup light. At that depth your traditional mass produced

underwater flashlights given enough dives will fail, which means you’ll be purchasing a reliable

backup light such as a Halcyon Scout Light

or

Light Monkey LED backup. Lighting is one of your most

because their dive stores are promoting big hand held lights for “night diving” and do not use lights to

communicate, to stow a long hose and to light up the underwater world in day and night diving activities.

Divers will also need a minimum of 2 cutting tools. We’d suggest a line cutter and trauma shears

dive knife, especially one leg mounted. See our blog on dive knife friend or foe for more details.

skill, confidence and familiarity. Renting this equipment is

not

and experience with different types of gear. Most dive accidents that occur result from divers using rented

or borrowed equipment, followed by lack of maintenance or modified equipment.

Buoyancy & Control:

like a NAUI Intro to Tech: A Rudimentary Elements of Diving course is going to take the recreational diver to that next level implementing the most modern skills, techniques, team diving concepts and equipment configurations. After successful

your depth and actually look the way a diver should in the water……trimmed out, streamlined, horizontal

I stress the importance of buoyancy control because only a program

completion of a course like Intro you should able to hover

motionless regardless of depth, fin forwards, backwards and turn

horizontally 360 degrees, manipulate your valves, do air shares at any depth at any time not wavering in

and with an absence of silt behind you.

Divers diving with Helium based mixes must have their buoyancy

horizontal and on an ascend not to be exceeding an ascent rate of

efficiently, but also because a diver who ascends too quickly will

recreational divers who have not received training through a modern facilitator of DIR based diver

is NOT

Divers who cannot control their depth without a reference can increase their risk of getting bent diving Helium based mixes which is why depth stabilization and buoyancy control are so important. A flat

spikey

If you are taking outdated training from a non DIR based instructor, a non cave diver, an uncertified or inactive technical diver or technical diving instructor, an instructor who doesn’t even get in the water with you or lets someone sign off your cert cards with a name different than the instructor who did the dives, or an instructor who is diving a different equipment configuration or mix (Closed Circuit Rebreather versus Open Circuit) than you then you are missing out on the best diving education possible, taking a short cut

horizontal stop is what every diver should try to achieve, while the average rec diver will achieve a

looking profile that we call a saw tooth because it will show the lack of control or up and down position of

the diver.

and typifying yet again why recreational trimix is not for you.

Team Support:

If you are diving with divers on air or nitrox while you are on helium you are on essentially a solo dive as you cannot switch to their mixes at depth in the event of an out of air situation or catastrophic gas loss or you can potentially bend yourself (next point) diving the same mixes ensures you can switch to your

do.

As a traditional recreational diver if you cannot handle a proper team dive implementing pre dive safety checks, bubble checks, safety drills either on surface or at depth, proper ascent not exceeding 30ft./min, hover horizontal in mid-water with no reference or just watching an anchor line or your other divers in the water recreational trimix is not for you. If you do not know what safety drills and bubble checks are you’re missing very crucial pre-dive skills.

Heat Loss and Helium:

Also note that divers often use argon over air because it’s 8 times denser and is a much heavier gas. Divers

Helium and the bends:

In the unlikely event of an emergency/panic situation where a diver ascends with no safety stop and goes directly to the surface they have a greater chance of

Nitrogen. This makes the gas less forgiving in the event of a free-flow/freeze up

to do find their dive buddy and ascend on their alternate air source or do a free ascent which will likely be conducted in a very fas manor as the average recreational diver would likely not be trained to handle any sort of problem in as calm and accurate manor as a diver diving in a team diving situation.

buddies long hose at depth and ascend symptom free.Having topside support for dives in the form of

emergency either above or below the water in mixed gas diving is also important.

Helium conducts heat away from your body 6 times faster than air which can cause helium to absorb

into the bodies tissues faster than it already does, as well as faster on gassing of nitrogen which can make

onset of Decompression Sickness more frequent.

always need to be surrounded in a heavier gas than what they are breathing. Helium is a poor choice and

can lead to Isobaric Counter Diffusion or ICD, please keep reading.

the bends as Helium absorbs into the bodies tissues 2.65 times faster than

where the average recreational diver would be in a single tank and would have

Divers need to practice regularly to anticipate problems and simulate how to handle them until these

problem drills are second nature and the diver does not change their depth, trim, breathing rate or have any hesitation handling the problems in simulation which will create body/muscle memory should a real scenario develop.

You MUST obey the safe ascent speeds. You must do a safety stop on every dive with helium. You must

be able to maintain your depth at all time staying within a depth range of 2 feet.

Since helium is a smaller molecule it will absorb into your tissues

faster and deeper than nitrogen which means bends can be more

serious too.

another mix. Switches should be conducted as shallow as possible which is why generally we ride trimix all

The problem with Isobaric Counter Diffusion is that it can be a debilitating injury which starts off

Counter Diffusion in plain english:

At this switch some divers would show signs of loss of balance and extreme vertigo and vomiting. The symptoms where identical to those of someone suffering from an infection in the inner ear,

specifically the semi·circular canals which are involved in control of balance. For many years it was thought that the bubbles causing the damage occurred in the vestibule part of the ear, hence the name given to that specific type of decompression sickness. It is now thought that the bubbles do not form in this region but in the cerebellum of the brain. This part of the brain controls muscles and receives the impulses from the semi·circular canals of the ear, hence the symptoms displayed. Wherever the bubbles occur the result is the same, severe disability which can leave survivors quadriplegic.

As you ascend, gas comes out of saturation and is removed from the blood by the lungs. If, however, you

the way up to 20′ where we switch over to pure oxygen to flush the gasses out of our bodies. This is why

ANY diver diving helium based mixes NEEDS to have a Drysuit Inflation System.

appearing to be a vestibular bend in the inner ear, the bodies primary sensory organ for spacial orientation

and balance.

I copied an article from my personal collection written by Fred

Winstanley who did a nice job outlining issues with Isobaric

switch to a different gas, specifically a nitrogen rich gas like air, the nitrogen dissolves into the tissues quicker than the helium can come out, creating a super saturation situation – hence bubbles of helium are formed in the blood. This bubble formation can occur with no change in depth, hence the name Isobaric, meaning “same pressure”.

How do we prevent this situation arising? The answer is quite simple, during decompression never let your partial pressure of nitrogen rise. Come as shallow as is safely possible on your bottom-mix, and avoid switching to air at any stage of the decompression, using nitrox or pure oxygen instead. This procedure will result in a slightly longer decompression profile but, remember, · you’re an awful long time dead.

ICD Defined: Tim O’Leary and Bruce Wienke define Isobaric Counterdiffusion as dissolved inert gasses moving in opposing directions in the absence of a change in absolute pressure. ICD can produce decompression sickness even without a change in ambient pressure.

We have even gone as far as to start using trimix as a decompression gas cutting deeper mixes with helium to prevent isobaric switches riding helium based mixes all the way up to 20′ where we then switch over to pure oxygen for the most efficient inert gas washout.

Because Helium in gasses and off gasses faster than nitrogen divers can decompress more efficiently while diving on trimix, but depth and ascent speeds need to be meticulous.

Exceptions for the Recreational Trimix Diver:

Because the average diver wanting rec trimix is thinking it’ll take them deeper with a clearer head they’re missing the actual advantages of helium which include cleaner on and off gas of inert gases, avoidance of nitrogen narcosis, as well as less breathing resistance from the regulator or rebreather creating less CO2 loading.

Several agencies use different concentrations of Helitrox ranging from: 26-30%O2/13-17% He……30% O2/30% He……25% O2/25% He.

GUE max training depth is 130′ but their mix should only used in 110-120′ to stay within PO2’s or 1.3ata and 1.4ata. They use doubles and a deco mix which technically makes it not a recreational diving course.

When reading through the course descriptions you will see them talk about different decompression and ascent procedures.

What makes these agencies an exception to us in the world of recreational trimix is that to train within those agencies divers need to make the commitment to take all prerequisite courses which can include a minimum of 3 courses all preparing divers for the next step in addition to completing a refinement course like NAUI Intro to Tech, as well as the financial commitment to all the required equipment.

The vast majority of instructors and dive training facilities currently promoting recreational trimix do not endorse the modern philosophies, team uniformity or gas matching methods that are required to teach/dive rec trimix and the divers taking recreational trimix are not learning a modern DIR philosophy if they’re not DIR divers. Furthermore, the programs often become sales pitch for rebreathers mentioning how every breath you exhale is wasted gas and how the recreational diver should then take a recreational rebreather course which sends the divers down a completely different path yet again rather than the diver developing into a solid open water, open circuit recreational diver.

The average recreational diver will not take the time to go through all of the training steps properly or as safely fast tracking themselves into a course where all you need is your advanced open water and basic nitrox. They often want the fastest course possible which is never a smart idea.

Divers should take pride in the fact that there are some agencies and instructors out there that put them through their paces academically and underwater building both body and mind for the rigors of deeper diving.

The way rec trimix is being promoted seems to focus on diving deeper without narcosis. The lack of prerequisite courses or additional courses one should take with it concurrently are lacking, much like the lack of skill development in traditional diver training.

Consider some Alternatives:

There is nothing at 110′ or 120′ that isn’t at 130′. Put in the time, get comfortable in the gear, take more shallow water training and when your skills are 110% then consider moving up into more fun courses like DPV: Diver Propulsion Vehicle using a proper/professional diver propulsion vehicle, not the little toys that most stores use. We have 3 Halcyon HDV’s in our rental plus 3 older units. A DPV can extend your bottom time and you can cover miles rather than feet underwater. That in itself awakens the explorer in people going where no one has swam before.

In the meantime why not look at more experience building courses like NAUI Intro to Tech which teaches you the fundamental skills like buoyancy, trim, fin techniques, equipment streamlining, deployment of all pieces of emergency equipment, basic rescue techniques, double tank an single tank valve manipulation simulating failed regulators/valves, line handling and awareness and so much more. After successful completion of intro look what can come next: Cavern diver, Wreck Penetration, Cave 1 , and so on.

Below is what I’d recommend the average diver consider as an alternative training option if recreational trimix is of interest to you and you want to be the best diver you can:

Open Water – Nitrox – Advanced – Rescue Diver – Intro to Tech – Cavern – Cave 1 – Technical Diver Level 1 (advanced nitrox/deco/helitrox) – Technical Wreck Penetration – Cave 2 – Trimix 1 – Trimix 2 – Cave 3 – CCR Diver/CCR Cave

If the diver completes the above course offerings they’ve taken the time to become one amazing diver.

Divers can have a lot of fun, staying within the NDL limits. They can partake in hundreds of dives at this level and then figure out if they want to extend their depth, skills and knowledge from there. After a commitment like the courses above they should have a better self image of themselves, as well as the opportunity to refine skills and enjoy practicing and learning with like minded individuals who want to challenge each other through skills dives on a regular basis.

You cannot dive trimix the way the average open water diver dives compressed air once a year. It requires discipline, dedication, finesse and skill.

Technical Diving: What’s involved?

After you complete Intro to Tech you should theoretically be ready to advance towards technical diving, as Intro is where you learn all the rudimentary skills every recreational divers should know and skills are honed, equipment configuration is streamlined, divers can start moving towards what some would call the “darker side” of diving. Dark or light, we have bigger, better wrecks and walls that you can extend your bottom time on rather than trying to do it half way on recreational trimix.

Technical Diving requires a time commitment as you progress through the ranks. We recommend taking the time to get experienced at every depth as your limits are increased while the divers are baby stepped deeper and deeper in the courses which even at the tech level start in 20-40′ of open water after a pool session or confined type open water depth. Once skills are completed over 3-4 dives in a confined water/shallow open water setting divers are taken deeper in a “mock” decompression simulating decompression dives and scheduled decompression stops.

Upon successful completion of the mock decompression dives we move the divers into real deco in the nitrox range (100-110′). Upon completion of those dives divers begin exceeding depths of 130′ utilizing Helitrox to a max depth of 150′. Throughout this program and a minimum of 14 dives, divers will have had a few weeks in between the practice with their team and review any additional skills unless completing

the course intensively over a week.

If technical diving was easy, everyone would do it, but it’s not for everyone and we feel that recreational trimix is just a short cut along the way taking divers down a path sooner than the vast majority are ready for. Have a look at our website for more info.

Technical Trimix Training and what’s involved:

As a store we’ve been teaching trimix since the late 1990’s. We’ve dove the deepest dives around, we’ve loved the benefits, but a true Trimix is for deep, technical wreck, cave, wall diving.

Divers diving in an overhead environment should be on trimix on anything deeper than 100′ which as we discussed at the start of this post is a depth where divers start suffering a mild impairment. Should a problem arise in an overhead environment divers need the helium to fight off narcosis and allow them to formulate the right plan of action.

Trimix requires double tanks filled with hyperoxic mixes of Helitrox for shallow tech dives, noroxic trimix for dives up to 250′ and hypoxic mixes for divers diving past 250′. We use decompression bottles ranging from 1 aluminum 40 cylinder to upwards of 4 40’s or 80’s for advanced trimix dives and a whole lot of experience at the deco/advanced nitrox/helitrox level before you even

entertain the thought of trimix.

Upon completion of Helitrox (150′) divers can participate in Heliair (180′ and has replaced Deep Air or Extended Range). Trimix L1 or just Trimix (200′). Trimix L2

or Advanced Trimix (250′ or 330′).
Trimix is awesome, helium is awesome, but it’s a tool just like sidemount, rebreathers, or any other piece of dive technology. Recreational Trimix is simply a waste of time and money for the open water, recreationally trained diver. There is a time, a place and a training sequence where Helitrox is beneficial and it’s not for the average recreational diver.

In closing after examining all the factors and discussing this topic among other Trimix divers and Technical Trimix instructors we do not feel at that trimix is a recreational diving gas that the average recreational diver should use. There is too much at to learn, too many skills you need, too much equipment to do it safely for the average recreational diver to start engaging in helitrox diving. Get involved with helium based mixes when you go tech.

In the meantime limit your depth, avoid narcosis, work on your buoyancy, trim, fin techniques and become a solid diver. Dive with us and we’ll help your diving dreams become reality.

We run Intro to Tech monthly, Technical Diver Level 1 courses twice a year, Trimix at least once a year, as well as Cave, Wreck Eternal Survey, Wreck Penetration, Technical Wreck Penetration and more. Don’t hesitate to get in touch with me and we can discuss training options.

See you underwater,

Matt Mandziuk [email protected]

1

ok I made it up to this point in editing but I need to take a break. Sorry, I’ll finish it up tomorrow!!

Grace Marquez 4 Jun, 2012 22:26