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Being an Active Scuba Diver

Being an Active Scuba Diver
by
Matt Mandziuk

If you want to dive, you need to make the time for it. Being and identifying as a diver are 2 different things and staying current with your skills, knowledge, training and goals are very important.

One of the questions we get a lot in diving is what doest it mean to Being an Active Scuba Diver?  You may have noticed after you were certified, you got really, really, really excited and interested in diving, meanwhile, some of your open water class certified down south, a couple of them didn’t finish, etc.

If a person wants to become an active scuba diver, they have to get involved.

Set Goals:

Why did you get into scuba diving?

Was it for a trip?  A documentary you watched?  A dream destination? An event like a wedding?  Regardless of the reason, there was something that motivated you to get into scuba and that is what you should hold onto.

As you accomplish each goal, set a new goal.

I look at my motivations for technical diving for example….dive sites like Bikini Atoll, Hamilton and Scourge (our local 1812 warships in 286′), the Britannic have all been dream dives for me since my teen years, and while I’ve been on an expedition team the last several years for H & S, Bikini was the one dream that came true, flying to Micronesia 27 years after I first heard about this nuclear radiated dive haven.

Current goals are still the one’s above, but also mine diving in Europe, so it comes down to putting your plan together, including team members and getting the required training (if required), permits, etc.

Training goals are also something to consider….a good diver is always learning and always challenging themselves to their highest level of experience/certification.

If you’re interested in diving more, there are several paths that can help you get more involved…the Local/Technical Diving path,  the Leadership Diving path, The Traveller Path….Ideally a combination of all 3 are our best option, making Option 4, The Total Diver, the Ideal DDS Diver 😉

Much like keeping up with your dedication to the gym, or a diet, keeping engaged in your leisure activities is key…

Dive Everywhere, Any Time You Can….

You’ll find diving much more rewarding when you can explore all aspects of the underwater world, not just reefs, not just wrecks, no just salt or fresh water, but all of it.

Diving icebergs can be as beautiful as diving a pristine reef in the Red Sea, while diving in a cave can offer a diver a prehistoric journey into the past, as you can see mammoth bones, speleotherms (mineral deposits like stalactites and stalagmites), or diving into the history of famous shipwrecks like the Empress of Ireland, Andrea Doria and more.

The journey to get to these destinations and having these dreams come true are the most amazing times too.

The people you meet, the destinations you visit, landmarks you see and photos you can take are what diving is really all about.

The entire experience isn’t just time spent underwater, it’s the history and the lessons learned along the way too.

Paths that Inspire

When people start to scuba dive, they have ideas, dreams, goals……following through with those plans is key.

The Local Cold Water/Technical Diving Path

You really wanted to get out diving, so you started diving weekly with similar minded people in the summer in wetsuits, however once you started training in a drysuit,  you noticed you wanted to go diving more and your wetsuit buddies didn’t, so you met some more drysuit divers and you had some great adventures.

While each your you’ll see new wetsuit faces on the boat, unless they move into a drysuit, those faces seem to change with each passing year, meanwhile the same drysuit divers are on all the same charters, trips and events, so after Open Water Diver, or as part of O/W or Advanced, combine it with the PADI Drysuit Specialty Course option.

Trippiest Diver Trevor

Why is that?  Because drysuit diving extends your level of comfort, extends the time you can spend underwater, rejuvenates your bodies warmth faster than a wetsuit and of course is a lot easier to get in and out of, layer up for added warmth, and they last a significant amount of time longer than a wetsuit which has a 2-4 year average life span or about 100 dives.

Drysuit diving also leads the diver into more exciting environments. 

Have you noticed that most of the drysuit divers are diving twinset double tanks? Rebreathers?  Sidemount?
They’re doing more exciting dives than just the local shallow shore dives in favour  for more exciting diving ventures like shipwrecks, caves, maybe even technical diving sites, but it takes time and skills to progress and in a society of instant gratification, sometimes people just want to do the bare minimum and that’s okay too if that makes them happy.

DDS Diver Starting his Rebreather Journey

So Divers if you want to dive more, get out, practice your skills with more likeminded people and challenges yourself through continuing education classes.

Whether you stay more recreational and participate in PADI Specialty training at the recreational level and work towards becoming a PADI Master Scuba Diver or you work towards a more technical path, an active diver who’s always learning is the best diver.

Moving into technical diving…Divers come from all over North America to train with us.  Why?  Because we offer the most thorough and rewarding technical diving training that embraces our training and experience we’ve gained from training with instructors (past and present) from  all training agencies.

Our NTEC Doubles Primer workshop/classes are the start of things to come for those wishing to start working towards their Foundational Skills classes like Intro to Tech and to get to their dream goal..  

Intro to Tech is the measuring stick for divers looking to become a better diver with buoyancy, trim, comfort and familiarity with their doubles setup.  Skills are broken down into specific sets that increase with each dive.  The class is video’d, students watch and debrief after each day in the classroom and upon successful completion are able to start accomplishing their goals like caves, wreck penetration, technical diving, diving with helium based mixes and more.

You’ll notice the technical divers are very active and very involved and that is what makes our diving community so special.  We have a lot of active DDS Divers who just love to get out and work on skills and mentor newer divers.

Diving can be the most extreme, or the most meditative experience in the world and the dive needs to find what “does it” best for them, but never limit yourself saying you’re “never going to….” and just get the most experience in as many environments as possible.

The most active divers are our cave and technical divers and aspiring one’s.

The Leadership Path

Divers interested in becoming a leader in diving, can work towards professional ratings, completing advanced, rescue diver and moving towards the coveted PADI Divemaster certification, which is the first leadership level (Professional) in PADI.  From there Divers can complete their PADI Assistant Instructor Class and PADI Instructor Development Course.

Dive leaders are an essential part of the training process.  If you think back to your open water class, there’s a chance you had a Divemaster to help acting as a role model and as an intermediary person to talk to between the you and the instructor, as sometimes students feel it’s easier talking to a DM rather than an Instructor.

PADI Instructor Development Course
DDS Instructors Unite during an IDC

Much like new divers, experienced divers need to keep active and challenge themselves.

We found that if a Scuba Diver doesn’t progress through training or challenge themselves to dive at their highest level, they have a 3 year shelf-life of being “stale” then the disappear.

Cave Divers are the exception so far……Cave Divers seem to stick with it and dive with us for decades.

So how does an experienced diver stay in the sport?  Challenging themselves to take a technical diving class like Decompression Procedures/Advanced Nitrox.  If they’re certified to that level then Trimix is their next class and then then should look at Rebreathers to save money on the Helium.

With a closed circuit rebreather, the diver can dive a full set of smaller trimix doubles that will save the diver multiple days of having to get their tanks refilled if they have a set of double LP50’s or so, as long as they don’t have to switch to open circuit during the dive, as the breathing efficiency of a CCR is on average 20:1 vs Open Circuit or better, so that diver who’d consume a set of doubles with 1/3 left for reserve will be using only a small amount of gas in comparison to open circuit.

The Traveller Path

A Diver should be as trained as is can be for their dream dive trip, but a vacation diver in a single tank setup can enjoy a lot of good diving around the world without having to go into a lot of extra equipment and training.  To do the diving as a recreational diver, a PADI Advanced Open Water Certification with Deep Diver Specialty will cover the average diver to their maximum recreational diving limit of 130’, but in addition to this, a Rescue Diver certification is also highly highly highly recommended, as you never know the dive buddy you’ll be stuck with as a walk-on on a dive vacation….Of course some folks would suggest they do a Solo Diver class to avoid diving with the bad divers also.

Solo Diver training is a lot of fun and very rewarding and it helps to start instilling some of the mindset and skills that a technical diver would utilize on a regular basis.

While most dive boats cater to recreational divers, there are definitely benefits to training up higher, as the wrecks get bigger, better and deeper, the reefs are in better shape away from the masses of divers who flock to the shallower sites, and more bottom time beyond what a single tank can offer is always a bonus.

At the end of the day, being an active diver is the most important thing.

There's nothing like waking up with the sun in a beautiful destination
Waking up with the sun in a beautiful destination – Sea of Cortez MX

An active diver is defined as someone who dives at least monthly to keep their skills sharp and practical knowledge fresh.  There’s nothing worse than an “experienced” diver forgetting how to assemble their dive kit on a dive boat.

Some of the most fun things that happen on a dive trip aren’t even necessarily things that happen under the water, it’s the fun and camaraderie are things that make you laugh and love being a part of the fun.

Liveaboard dive trips are the best value in diving and being at sea for a week means you get to explore the farther away sites that a land based operation can’t journey to.

We’re an authorized reseller for the finest liveaboard operations around the globe and we’re always looking for the next best, next exciting, newest to us destination.

Break the cycle of diving the basic, more public areas and explore more special, road less travelled destinations.

Our Red Sea trip was a huge success this past December, with a lot of exciting trips to Malta, Maldives, Philippines and Micronesia and Europe either booking or being booked at the time of this writing.

The Total Diver

The scuba diver that is active in all environments, all season long who is an active recreational, cave, technical diver are the ideal role model and the ideal candidate we target when we hire Instructors.

Many of our divers are divers who have been diving for years, logged hundreds of dives and have spent time mentoring and encouraging new divers, advanced and experienced divers and who also enjoys travelling, exploring and everything that diving can offer.

A role model and leader in diving is a professional who logs as many dives for fun as they do for teaching, as there is so much more out there to explore.

Dive with a group of likeminded divers, don’t limit yourself to just 1 or 2 people, because as we often see, a traditional buddy team fades when people have a life changing event, and often times the more keen diver sites on the bench wishing they could dive.  So, just come out and dive with the most active dive shop in the business, here at Dan’s.

Beautiful sunset on Georgian Bay

Travelling divers explore the world more than their own backyard, yet North America offers the some of the best diving in the world, as does Europe, it’s not just about tropical adventures, but exploring what’s in your country, and Canada has some of the biggest and best shipwrecks, deepest walls and most beautiful scenery.

We’re located in St. Catharines, ON, Canada, but we dive the planet and explore and enjoy diving still after all these years!

If you’re looking for amazing places to dive, consider local diving like Tobermory, Kingston, 1000 Islands, Straits of Mackinac.  Travel within Canada to Newfoundland and British Columbia, as well as Quebec and see the beautiful reefs and wrecks.

Where should you dive?  Anywhere we’re excited to go is a great start!

Join us on trips, charters, social events and training check our events regularly CLICK HERE

 

DDS Diver Grace doing a CCR Trimix Dive in Bon Echo Park

When Should You Get a Rebreather

When Should You Get a Rebreather
by
Matthew Mandziuk

Lately people have been asking us about rebreathers and when they should consider going that direction…So I figured “When Should You Get a Rebreather” would be a fun topic to write about.

Rebreathers are a simple concept.  A rebreather is in essence like breathing from a “sealed bag” is filled with a breathable gas mixture.  As you breath each breath, you deplete the oxygen in the “bag” through the process of metabolizing the oxygen and putting back in the lung exhaled breath with a lesser partial pressure of oxygen until the “sealed bag” or “lung” would go hypoxic (think of breathing in and out of a paper bag as a concept), meaning not enough oxygen is in the gas you’re breathing to sustain life.

You would have to replace the depleted oxygen with more oxygen, but in addition to this, you’ll also have make sure that carbon dioxide is also being absorbed/eliminated from your rebreathed gas, so we need to “scrub” the CO2 out with a CO2 “scrubber”….Sound simple?  It is overall.

Below we will discuss who should dive a rebreather, the different basic designs and features, key elements, dive planning and more.

There are 2 main rebreather concepts.  Semi-Closed and Fully Closed rebreathers.

fathom rebreather rigged up as the tech version with faber LP50 tanks, Lola valves, atomic regulators, custom black camo halcyon evolve jj wing with maroon center, spg on left hip with diluent injection through the left hip d-ring
Fathom MK2.5 CCR Tech Rigged

Semi-Closed is less popular for the vast majority because it’s a glorified gas extender with an efficiency ranging from 4:1, 8:1, and as high as 10:1 efficiency depending on the gas supply.  They can use the same lung that a life-support patient breaths from which passively allows excess gas to vent from the bottom of the unit while the lung is refilled.

The Passive Semi-Closed Rebreather is very popular for depths where open and closed circuit scuba are less reliable.  PSCR Divers often use larger cylinders.

Fully Closed Rebreathers utilize smaller tanks, a greater degree of efficiency as high as 40:1 that of open circuit because when the efficiency is met, the diver recycles the entire exhaled breath and only has to inject the oxygen when the PO2 drops.  They can be more complicated but are more popular at the time of this writing

Rebreathers ARE NOT For Everyone

With the Cost of Helium increasing, more and more people are looking to breath more efficiently, however, diving a rebreather requires a higher level of awareness, technique, buoyancy, trim, knowledge of the machine and what can go wrong and how to troubleshoot problems.

It’s only a matter of time until Rebreathers become more common practice to the masses, however, now is not the time for most people because they don’t have the training or the experience.

Helium keeps going up and up, but that doesn’t mean unqualified Divers should be jumping in blind and bypassing all the experience and fun that is had learning and logging the experience dives that makes a person a better Diver.

Here are illustrations of a basic rebreather design and semi-closed rebreather design courtesy of the NAUI Rebreather Instructor Guide.

SCR Rebreather
SCR Rebreather
Closed Circuit Rebreather Diagram
CCR

Types of Closed Circuit Rebreathers

Choosing the right rebreather for the individual is key.  There is no perfect one rebreather of everybody.

Automatic: Some Divers prefer an automatic rebreather than much like a dive computer, runs the dive for them setting a constant PO2 (oxygen set point) for them on descent and maximum depth injecting oxygen using a solenoid .

Unless the Diver remembers to set the computer to a lower set point on ascent, this can cause problems for the Diver as the unit will continue to inject oxygen as the depth reduces because as the diver goes shallower, the Po2 will drop, so if the Diver ascends from depth at a PO2 set point of 1.2ata the rebreather will try to keep filling the lung with oxygen, whereas, the diver needs to set their set point lower to 0.6ata and they can ascend without worrying about an out of control ascent and manually adjust their set point to their desired level.

Continuous Mass Flow and Needle Valves: Some rebreathers use what’s called a needle valve which uses a “Mass Flow” orifice on the regulator of the O2 tank. The Diver can set their oxygen set point based on their metabolic oxygen rate by adjusting the Needle Valve.

The needle valve will gently flow oxygen into the counterlung so if the diver becomes task loaded and isn’t watching their Po2 (which should never happen), they needle valve will prevent the Diver from going Hypoxic.

You’ll find the Mass Flow a great option which is why the original KISS Rebreathers are still one of the simplest designs, while the updated Needle Valve design of Fathom CCR  is becoming so popular.

The Continuous Mass Flow system is limited by depth.  The intermediate pressure of the regulator first stage can reach the same as ambient pressure meaning an intermediate pressure in the first stage of 10BAR/145psi will not put out any more gas past 81msw/260fsw.

The Fathom System corrects the by modifying a diaphragm sealed first stage with a stronger spring which allows for safe boosting of the intermediate pressure up to as high as 205psi/14BAR which is capable of diving to depths of 120msw/395fsw.  The pressure can also be increased up to 290psi/20bar for up to 585fsw or 177msw!!!

Excerp from the Fathom Page: “Smaller fixed-orifices can also be used for deeper depths with higher intermediate pressures but the risk of a blockage is increased and the options are limited by orifice availability. A fixed-orifice requires that the first stage intermediate pressure be adjusted to achieve a flow rate that corresponds to the diver’s metabolic needs, typically around 0.6 to 0.8 L/min. Conversely, the needle valve allows the first-stage intermediate pressure to be set to any pressure since the needle valve handles the flow adjustments. More importantly, the needle valve minimizes the risk of a blockage from debris since it can be opened up to allow small particles to pass. The oxygen MAV, which contains the needle-valve, is ported directly into the exhaust side of the head so oxygen must travel through the scrubber and mix with loop gas before reaching the diver.

1 (145 psi/14.7 psi/ata – 2 ata) x 33 fsw/ata = 260 fsw  (Note: always subtract 2 ata when calculating the maximum operational depth of a CMF system.)”

Diving the Bell Island Mine with Explorer and Rebreather Instructor Matt Mandziuk

Manual CCR: Manual Rebreathers are simple, easy to use, but require more attention to the instrumentation and require the operator to constantly inject oxygen based on their needs depressing an oxygen injection button allowing the Diver to adjust the oxygen as slowly or quickly as needed, in a similar fashion to how a diver would inflate their bcd.

When Diving a Manual CCR, the Diver will have to remember to monitor their Po2 and maintain the desired set point.

One of the more fun skills is “Volume Drop” which the CCR Diver will do in their initial training course to see how long it can take their mix to go near hypoxic from their targeted set point.

Keeping a consistent set point that mirrors a backup computer if there isn’t a second computer handset or NERD on the unit is a desired option.

Being diligent with keeping the oxygen level consistent is a must.

Simplicity and Reliability Should Favour Bells and Whistles

The more high tech of a rebreather, the more complacent some Divers get.  Whether you’re flying an automatic or manual system you should always be aware of your set point and Do Your Pre-Dive Checklist!

A Rebreather is a very Serious Piece of Equipment.

PSCR Rebreather
Semi Closed Rebreather Rigged and Ready to Dive with double 80’s in Mexico

A rebreather is essentially a nitrox or trimix gas mixing system that is designed to deliver a constant oxygen set point that acts as a gas extender to you diving more efficient.

With each exhaled breath you make on open circuit scuba, there is no way to get that exhaled gas back.

A rebreather recycles your exhaled air, which is typically 5-6% less oxygen than you inhaled.

When you exhale into a rebreather, you’re exhaling into a scrubber canister, which is essentially a “filter cartridge” that is filled with a carbon dioxide absorbent, a granual that traps the CO2 on granules that resemble kitty litter called Soda lime, which is used to remove CO2 from breathing gases to prevent CO2 retention and CO2 Poisoning.

The filtered gas enters a counterlung that allows you re-breath this recycled gas and as it continues to be re-breathed, oxygen has to be added on occasion to prevent hypoxia (not enough oxygen)….Some have said that a rebreather is “essentially slowly trying to kill you, so maintaining the oxygen levels is essential.”

With each breath in we drop our oxygen PO2 so as the levels drop, we need to add oxygen to “bump” up the levels or the oxygen percentage you’re breathing can go hypoxic meaning you don’t have enough oxygen to sustain life and can go unconscious and die.

White Arrow Axial Rebreather Scrubber Canister
White Arrow Axial Rebreather Scrubber
fathom rebreather scrubber regular and large size canisters
Fathom Radial Rebreather Scrubber by Golem Gear

Think of the Scrubber and counterlung as your cardiovascular system.

Radial vs Axial Scrubber

Radial Scrubber allows the gas to pass through he canister body and provides a lower work of breathing, but is more difficult to pack than Axial Scrubber canister.

As the Co2 Absorbent becomes wet through moisture/condensation, the absorbent can clump, which can make it more difficult for the gas to pass through it, thus increasing the work of breathing.

Axial scrubber size/length needs to be long enough to prevent channelling of gas and short enough to keep the work of breathing low enough.  A longer Axial scrubber will increase work of breathing.

For longer dives, a longer radial canister is much preferred as the work of breathing remains excellent on most designs.

There are also pre-packed scrubber cartridges available for some models of rebreather for the Diver who doesn’t want the responsibility or liability of packing a scrubber canister.  These are more costly, but effective.

Rebreather Fatalities are (approximately) 10 Times More Common than Open Circuit Scuba Fatalities

Diving a Rebreather is very different than diving traditional Scuba. You can’t control buoyancy the same way and they don’t deliver gas the same way. Some even have a very complicated bunch of electronics or bulky, dangling bits everywhere and a huge, bulky counterlung.

Many CCR Divers can’t do a “try dive” on the unit they think they want to buy, so unfortunately, we see many people making Very Poor Choices in their Selection.

Your best rebreather is ultimately the one you think you want, but honestly, the simplest, most reliable and mores streamlined rebreather is the one for you.

Avoid Bells and Whistle’s, and run the unit in “manual” mode instead of an automatic rebreather. Be In Control of Your Oxygen Levels, don’t trust the machine to do it all for you.

Get as polished as you can be and as experienced as you can be before you jump into a rebreather.

Who Should Dive a Rebreather?

If the CCR Diver is wanting to dive the a pair of shipwrecks within recreational limits and dump their scrubber after the dives are completed, the cost of absorbent and gas fills will cost more than Nitrox fill in doubles would, so unless that Diver is planning a longer than “No Stop” recreational time limits, or saving the absorbent after the days diving wraps up for another day of diving, there is no benefit to using a rebreather on those dives, other than practice.

Cave Divers can spend hours underwater just on a single dive, as can shipwreck divers, technical divers and research divers.  This is who a rebreather is best suited for.

NEVER ABANDON HOGARTHIAN/DIR/NTEC PRINCIPLES AND VALUES

Your rebreather configuration should be as streamlined as your doubles setup. Simple, Streamlined, Reliable, Familiar. Long hose is always off the right post, necklace (or BOV)  is always off the left post so they don’t roll closed when swimming through a restriction like a cave or shipwreck.

Most CCR Divers Don’t Mirror Open Circuit (Long Hose, Backmounted Diluent, SPG Left Hip, etc.), which makes the system more complicated and in a situation where task loading can become a problem, that’s never good.

200′ Trimix Dive with LP50’s, argon, Nitrox 50 and Oxygen

You should NEVER have to re-orient your stage bottle rigging (Always Valves Up Not Valves Down), positioning of your stages (Always Left Side). Running your valves “Valves Down” means your regulators are going to hit first when you do a stage drop.  Those diving in the Great Lakes also have to worry about Zebra Muscles slicing into your hoses.  It’s also easier to do a bubble check when your stage bottle valves are facing you.

Valves Up? or Valves Down on the Main Cylinders?  Diving 3L Cylinders you will trim out better with the valves upright like a standard K Valve, but the Valves Down is acceptable for some configurations too.

When Diving CCR with Aluminum 40’s or Faber LP50’s Valves Up is the Most Modern and Most Reasonable Option.

Diving PSCR Valves Up is the Only Option as well, since the cylinders are larger and your’re mirroring your Open Circuit Doubles Configuration.

You can also get a Sidemount Rebreather in PSCR or CCR.  Many of them do not breath well.

Remember the DIR…NTEC Principles are based around the concept of “Doing it Right”.

Another Type of rebreather….Chest Mount

Rebreathers like the Dive Rite O2ptima CM and Sub-Gravity FX CCR are chest mounted rebreathers that allow the diver to keep their original back or side mount configuration.

The units sit on the front of the body and have been used by the military and White Arrow Divers for decades as a decompression rebreather, but are improving in popularity for their attractive price tag, work of breathing and travel friendly size.

Not Enough Bailout Gas

One of the most common problems with rebreather divers is that they do not carry enough bailout gas!

You’ll sometimes see a cave or trimix diver doing a technical dive with 1-2 aluminum 40 cylinders.  In the unlikely event the diver is equipped with 3L (FX23 cubic foot) tanks, they should have a minimum of 2 stages.

Some Divers are also starting to use a Sidemount Rebreather as a bailout option.

Cave 1 Divers require a minimum of 140ft3 of bailout, while a Cave 2 level Diver requires a minimum volume of 225ft3.

This means that the average CCR Diver doing a cave dive with an aluminum 40 or a pair of 40’s isn’t carrying enough bailout in the event of a full failure of the unit where they’d be required to swim their bailout from the deepest point in the cave.

Even an AL80, AL40 and the 3L tanks aren’t generally enough for a cave 2 level dive, 2 80’s and bailout in fact aren’t either as that + the 3L cylinders is only 200ft3 of gas.

A recreational diver doing No Stop Diving can use a single AL40 from 40msw/130fsw.

A Technical Level 1 Diver 50msw/150fsw would require an AL80 and an AL40 to ensure they can hit the obligated deco stops ascending from max depth to first deco stops and in the second bottle should have at least a 50% nitrox mix to breath.

A Trimix 1 Diver (2 deco bottles in Open Circuit) generally certified to 60-72msw/200′-240′ should have at least 1 AL80 worth of bottom gas to ascent from max depth to first deco stops. A second AL80 to ascend form the 150-70′ range and then enough gas to get from 70′ to the surface.

A Trimix 2 Diver diving beyond 70msw/240fsw requires enough bailout to ascend from max depth to first deco stop, and then each additional phase of decompression.

A 91msw/300fsw would require roughly 150ft3 of open circuit bailout to the first required deco stop, which would be a trimix of a 21/35 or 23/25.  That would have to last the OC Diver up to the next required deco phase which should be 70′ and 50% Nitrox or a hyperopic trimix like 50/25, while others may opt for a 30/30 trimix breathed up to 20′ which would require yet another AL80 for the decompression phase.

You’ll start to see why the little 3L tanks aren’t enough for deeper trimix dives unless you split the bailout cylinders with your team member(s) to minimize what you’d have to carry.

For “Light” recreational dives, double Aluminum 40’s are a wonderful option offering 80 ft3 of bailout on the back.

SCR Rebreather
Try and Discover Rebreather Experience Today

A pair of Faber LP50’s filled “Florida Style” with a bottom trimix is more preferred for experienced rebreather divers.

For the Same Dive the LP50’s would bring the diver into the 55msw/180fsw range easily, switching to the 21/35, then up to the next deco phase at either 21msw/70fsw or 30msw/100′ and up to the 9m/20fsw phase where another AL80 of oxygen would be required.

It’s so important to plan ahead and plan for the worst, as you don’t want to be left with any surprises, and while a flooded rebreather or a total loss of your PO2 monitoring equipment is rare, which can happen, as can regulator failures, burst disc ruptures and more, but that’s why they call them a failure.  They’re unplanned.

Being Proficient in at minimum of 2 AL80 Stages is why I always encourage Divers to get to at least the Cave 2 or Trimix 1 level.

Maintenance

The pre-dive setup and post dive teardown of a rebreather could take far longer than the planned dive. Some units are easier to assemble and teardown than others, which should be a consideration.

Maintenance, pre-diving evaluation of all components which should be frequently inspected, as well as changing of the oxygen sensors every 6-12 months, servicing the regulators, fittings, o-rings, injection equipment should all be factored in.

If a leak is detected in the unit, it can cause more problems in the event of an emergency, as a flooded rebreather can have an unfavourable effect if the scrubber becomes wet, causing a “caustic cocktail” which can be an instant retching action that can cause the diver to go into a choking reflex as you ingest this corrosive, alkaline cocktail.  If a Diver tries to bail out to open circuit on a separate regulator they may involuntarily inhale more water, while simultaneously retching and possibly drown, this is where a Bail Out Valve or BOV is a very smart piece of equipment.  The BOV has a switch on the rebreather that allows you to open the breathing loop from closed circuit to an open circuit regulator.

The diver will then be able to breath or barf and breath through the second stage as they take sanity breaths for a couple of minutes.  Students are taught to purge empty the rebreather from water on their CCR Course.

Instead of a BOV, some rebreather divers use a DSV (Dive Surface Valve) to allow them to breath surface air topside.  This could be more risky in a caustic environment as the diver doesn’t have the ability to switch off closed circuit to open circuit in the even of a caustic cocktail, so utilizing a necklace under the chin reminiscent of how modern divers dive with a long hose/short hose configuration is the only reasonable option to get breathable gas if the unit is flooded.

People love the “Cool Factor”, but I wholeheartedly caution those who don’t cut it at the recreational or entry-level technical diving level to wake up and seriously ask yourself if you’re ready for all that CCR Diving entails.

A friend of ours who passed away recently ago used to say he never dove a rebreather because he had friends who were Doctors or Lawyers with more letters that were in front of their names who died on them.

Diving a Rebreather is more commonplace now, but unless the dives are super deep (below 150’ or more) or super long like those maybe a Marine Research Diver would be participating in, the reality is that diving Open Circuit is the more efficient choice for the average person.

Rebreathers require a much higher degree of attention, diligence and understanding of how the unit works.  The simpler the unit, the easier it may be to fix on the fly in the event of an equipment related issue.  You should always have multiple ways to receive breathable gas in an emergency, so always do your positive and negative checks, and test out the mushroom valves, regulators, fittings and practice drills regularly to keep your problem solving skills sharp.

Have a well stocked rebreather Save a Dive Kit of spare o-rings, regulator parts, breathing hoses and sensor(s).

Keeping Your Rebreather in “Dive Ready Condition” is a Must.

Pre-Dive Checks, Calibrating the Instruments, verifying flow rates (if applicable), packing your scrubber, then cleaning and disinfecting the unit is all part of rebreather diving.  Don’t be lazy and don’t be complacent.

Diving a Rebreather requires diligence and being familiar with all the inner workings of the unit.

Things to Consider.

Which Side does the oxygen inject in from?  Before or after the gas is analyzed? Does it have an ADV or a T-Block Piece?  How many different ways can you get breathable gas if you need it?  How does the unit breath flooded? Is the unit reliable?  Does it work in cold water or just warm water?  Is it lightweight for travel? Do you need to wear weights with it and how much?  Is the cost of the unit agreeable?

What are the entry requirements to training on a Rebreather?  Agencies who make it “too easy” don’t get the big picture.  Train harder, skill up and then go to a rebreather.  Don’t Take Short cuts.  See my previous blog post What’s The Hurry, What’s The Rush?.

You’re making a decision that can cost you over $10’000.00USD.  Do Your Research, but more importantly talk Us.  We do get Demo Units as well sometimes as trade-in’s.  We currently have a Sentinel CCR up for grabs.

Book a Try Dive with Us and see why our way is the best way.

All too often Divers go blindly into purchasing a rebreather and it’s not until they start putting the hours on their units do they realize they purchased the wrong one.

In Closing

Rebreathers are a lot of fun, as you can extend your dive times, see more creatures up close and more personal, it buys you time in an emergency if you’re trapped in a shipwreck or a cave to find an exit in the event of a collapse making them a safer choice for extreme cave diving and the deepest shipwreck diving.

50-100 Trimix Dives will more than pay for the rebreather and the training, so get your hours up in Open Circuit, get proficient with multiple stage bottles and let’s help you become a Rebreather Explorer.

Unmasked A Modern Look at Scuba And Snorkel Masks

Unmasked A Modern Look at Scuba Masks And Snorkel Masks

Today we’re going to talk about Scuba and Snorkel Masks, which also hold true for FreeDiving applications.

Many Divers and Snorkels ask us “What’s the Best Scuba Mask?” Our answer is simple….The one that fits you best. Read on and learn the additional features that will make your dive mask the best.

Question For You:

Have you ever been to a resort where someone just hands you a snorkel mask our a dive mask out of a bucket and tells you to go and enjoy the water?  For some that can be a wonderful eye popping experience and for others it can be painful, irritating, uncomfortable or downright unnerving.

Today we are going to discuss some of the key features, technologies, materials, styles and levels of comfort you can come to expect from a good quality scuba or snorkel mask.

Hopefully this will help you pick out the best scuba mask or snorkel mask for your every day water related activities.

Key Features

Some would argue that the more expensive the mask is, the better it will fit you or the better quality it is.  This isn’t quite the case.

The best mask on the market is the mask that fits your face first and foremost.

Factors that affect the fit of the mask are face shapes, facial hair, buckle or strap design, single or double lens, type of mask skirt material, lens glass and frame shape to name a few.

Generally speaking the bigger the face the larger the mask skirt and frame will have to be.  Someone with a narrow face like a woman or small child can fit a small to mid size frame, while most average size faces would benefit from a standard fit, larger faces may require a wide fitting mask.

There are a handful of brands who offer small/medium fitted masks, as well as wide fitting masks, while the norm is to make a mask for the average face.

Once you’ve determined the size of mask you may need its time to weigh options, for example, if you have facial hair, you may favour a stiffer mask skirt with a frameless designed that will sit slightly higher above the moustache versus one that lays across the hair preventing a full seal against the upper lip and under the nose.

The Moustache: Moustache divers or snorkelers can be one of the more challenging people to fit, so we often gravitate to a few good “moustache masks”.  These masks are shorter and stiffer in the upper lip area and aren’t as affected by the facial hair which can break the seal of a softer skirted mask.

The BARE Frameless Mask, Atomic Frameless Mask, Mares X-Vision standard and TUSA Powerview have been some of our most successful options.

Avoid The Dreaded Purge Valve!  Rather than going for a proper fit, some people choose to go for a mask with a purge valve in the nose that allows you to simply blow out to evacuate water, which is great, when they work, however, we believe a purge valve mask is an excuse for an ill-fitting mask.

Purge masks also tend to fail over time having the valve curl or simply falling out causing the mask to fill up with water, so for this reason we simply don’t recommend or endorse the use of purge valves in masks, but are happy to add one into any mask you desire should you want one.

Wearing a Skirt?

Guys and girls both wear skirts when wearing a mask.  So what’s the difference in mask skirts?  Mask skirts can be made of a number of different materials including Rubber, TPR (transparent rubber), PVC, Silite, Silflex, Silter, Silicone, Crystal Silicone, Liquid Silicone, Liquid Crystal Silicone, Gummybear Silicone and more.

Rubber was the most common type of material throughout the infancy of snorkeling and scuba because it was inexpensive, created a seal, was black which helped the person see clearer without glare and refraction of light, but it was not a product that had offered a lot of longevity, however, in the late 1970’s silicone started to become more popular due to the fact that it didn’t break down in the sunlight, was more comfortable and chlorine resistant.

Alternatively TPR, PVC, Silite, Silflex, Silter are all harder skirted alternatives that cost less, are replaced more and are often found in the department stores.  Some manufactures promote a silcone mask/snorkel combo, however, a mask can be class as “silicone” with as little as 5% in the skirt.

You can tell how much silicone is in the mask vs. plastic or other materials by holding the clear skirt up to the light.  If the mask has an opaque colour that looks “clumpy” or more white it isn’t pure silicone.  If the mask skirt has an odour the smells like chemicals, its not pure silicone.

Many of our dive mask brands offer both “sport” quality and “dive” quality. Both can be suitable for snorkeling and in some cases diving too, however, fit and comfort are the 2 most important factors affecting your decision to purchase one over the other.

Pure Silicone mask skirts are still the most comfortable, last the longest, do not break down with repeated saltwater or chlorine immersion and are UV resistant.

Silicone masks can come in skirts that are acid washed to be perfectly transparent or they can be coloured black or other unique colours.  At DDS we prefer black silicone because it offers better vision through the process of eliminating excessive amounts of light which flow in through the normally clear skirt and then cause glare and refraction of light when compared to their black skirted brethren who provide eye and glare protection and less overall strain and eye fatigue.

Clear Skirted Masks Yellow over time.

Black skirted masks also age better maintaining their black colour, whereas clear skirted masks only stay clear for a little while, that is until the uv rays, dirt, sand, rubber and other factors start to cause a yellowing of the skirt and they become opaque over a rather short period of time, meanwhile the black skirted mask is still looking as fresh and good as it did the day it was purchased.

Regardless of the mask you choose it’s all about fit and comfort.  You can read review after review, but the mask should be fitted by a professional who understands your needs, wants and has a good selection.

We sell virtually every brand of mask, but have cherry picked among our entire staff the masks we feel to be the best fitting masks on the market.

Keep the gimmicks to a minimum.

The Fit

Make sure when you’re wearing your mask you can equalize your ears by squeezing your nose pocket, this will ensure you can get to the nose pocket when you need to.

Make sure the mask strap isn’t too tight.  A proper fitting mask only needs to have the strap snug, not tight because the water pressure is going to keep the mask on your face for the most part too.

Make sure the mask doesn’t sit against the brow area putting pressure on it if its a 2 lens mask (men generally have a protruding brow).

Make sure the nose pocket doesn’t dig into the bridge of the nose.

Wear the mask strap just over top of the ears centering it around the middle 1/3 of the skull.  Wearing it too high can cause the mask to push up under the nose causing chaffing and making it raw over time, so really pay attention to centering it and keeping it adjusted comfortably.

When wearing the mask you can check for proper width by looking in a mirror.  You don’t want to see the skirt too narrow that it sits on the eye, but you also don’t want it so wide that it lets water in through the top or sides.

Breath in through your nose without using the strap, see that the mask sits comfortably on the face.  If it does, put the strap on, snug it up comfortably and with the mask against the face exhale.  The exhaled air should go out the bottom of the mask not the top of the head by the temples or above the eyes.

High or Low Volume?  Which is Better?

Low Volume is always best.  The lenses sit closer to your eyes.  There’s a smaller airspace to equalize the masks internal airspace which is something you’ll notice when you go down on breath hold or on scuba.  With increased pressure the mask will suck to your face more and more and more eventually causing pain and discomfort.  To avoid this you’ll need to equalize the airspace by simply blowing some air through your nose into the mask to keep it from squeezing down.

tusa_panthes_mask_for_sale_online_in_canada
Black Skirted Masks maintain their colour and help eliminate light glare

Lower volume masks are more comfortable and are easier to clear water out of as well.  Imagine a big round window shaped mask and how big and how much water can fill that mask up.  Now picture a streamlined mask that has a similar surface area to that of a pair of swim goggles but with an enclosed nose so you can blow into it.

Which mask is going to be easier to clear the water out of ?  The one with more or less water in it?  If you guessed less water in it you’re right.  The smaller the masks overall internal volume the easier its going to be to blow the air out of it.

Frame or No Frame?

Divers have long gravitated towards plastic framed masks that press the glass, plastic and frame all into one package with a lens retainer.  They’re durable, comfortable, most popular.

Frameless masks are a more modern concept that has less overall parts and simplified construction by simply moulding the silicone frame over the tempered glass lenses and bonding the silicone to the skirt.

The Different Mask Lenses

The market for different dive lenses have changed a lot since the initial introduction of simple tempered glass or polycarbonate lenses.

Tempered Glass lenses are still the industry standard because of their durability, relative cost effectiveness and the fact that they don’t shatter inwards due to pressure.  They can break like anything else, but generally the glass will stay together.

Tempered Glass is durable, they aren’t affected by scratches in the water, but they do have a greenish tinge to the glass which cuts back on light transmission.

Polycarbonate is plastic, scratches very easily and not suitable for scuba diving or much more than pool playing.  They’re typical of your department store masks which are cheap and not designed to last.

Ultraclear Glass Lenses introduced by Atomic Aquatics

Ultraclear glass is an optical quality glass with exceptional clarity and high light transmission, with no colour distortion.

Standard float glass (tempered glass) lets through approximately 86% of the available light but UltraClear lenses can allow up to 92% light transmittance. Combine that with the increased colour vibrancy and clarity and you’ll never want to dive with a standard lens again.

ARC Lenses or Anti Reflective Coating Lenses Introduced by Atomic Aquatics

Between 4-14% of light can be reflected back or “lost” by the standard “green float glass” mask lenses used by the more traditional mask makers.  ARC technology lenses are especially important for SCUBA divers underwater, where available light is quickly absorbed by the surrounding water because they help amplify available light.

Atomic Aquatics ARC Technology to reduce reflected light and actually increase the amount of available light transmitted to a diver’s eyes. The result is a greatly improved transmission of 98% of available light, compared to a loss of more than 14% of light with standard green “float” glass used on the majority of masks on the market.

ARC uses a multi-layer metal oxide coating process applied to both sides of the UltraClear lenses. This allows more light to enter the mask by reducing light reflections off the inside and outside surface of the lens. The metal oxide coating is only a few microns thick.

Anti-Reflective Coatings or ARC is a multi-layer metal oxide coating process applied to both sides of the Ultraclear lenses. This allows more light to enter the mask by reducing light reflection off the inside and outside surface of the lends. Clearer, crisper vision.  Reduces eyestrain, glare and prevents ghost images on the viewing area of the lens. A must for night diving and limited visibility conditions and underwater photographers.

 

Mirrored Lenses

Some Divers like the idea of mirrored lenses, however, they reflect back at the fishlife and can cause unwanted confrontations.  They also hide the divers eyes, which are essential when assessing diver comfort underwater, so for this reason we’d suggest staying away from mirrored lenses.

Types of Mask Straps

DDS Neoprene Mask StrapMost mask straps are made of the same material as the mask.  They’re designed to fit comfortably, not overly tight around the back of the wearers head and have side adjusters that allow you to often times pull the mask strap by tabs to tighten it.

The straps can pull hair or can tend to be uncomfortable.  One way we fix this is by adding a neoprene mask strap backing or replacing the entire strap with a neoprene adjust-a-strap which uses Velcro on the sides and neoprene on the back of the head.

You don’t need hair to enjoy a neoprene mask strap, they’re the best option for ease of donning or taking your mask off, plus they also float a little bit, so if you drop you mask into the water you may have faster response as it may not sink immediately .

Prescription Lenses

We can get a number of masks with prescription lenses.  We carry lenses in + or – diopters, as well as custom ground lenses for people needing lenses for different pupil distances and special features.

The costs of lenses for negative diopters are very reasonable.  Positive diopters are more expensive.  Standard bio-focal lenses are also available.

We generally recommend TUSA or Atomic for prescription lenses.  They’re easy to install and the masks are the best quality you can buy.

Replacement Parts

When purchasing a mask consider the fact that this product will last you 20-30 years if you look after it.  My personal TUSA mask is one I’ve had since 1996.  Dan had a 30 year old TUSA mask.  When you buy quality products from reputable manufacturers who make their own masks (NOT OEM with a Log slapped on) you purchase a product that is going to have parts and service around for years (or decades) to come.

Mask clips can commonly break if dropped or stepped on.  Lenses can chip, mask skirt scan rip, lens retainer clips can break if you’re cleaning the mask and mask skirt on a regular basis.

Brands like TUSA, Atomic Aquatics, Mares Diving, Problue and Scubapro keep a range of clips and replacement parts in stock.

Pre-cleaning Your Mask

Pre-clean your mask with toothpaste rubbed on the inside of the glass and take a toothbrush with mild abrasive and brush the inside glass to remove a protective silicone residue that is tacked on the inside.  You can also carefully burn it off with a flame if you have a steady hand and trust yourself around silicone.

Pre-cleaning the mask will help prevent fogging and will give you a better chance of fog-free diving.

Defogging Your Mask

Mask defog is your friend.  Not because we’re a dive store, but because you don’t want bacteria ridden saliva in your mask that you may or may not fully rinse out.  We’ve seen divers with eye infections from using the communal “spit bucket” on the dive boats down south where 10-20 divers are all spitting in their mask and then rinsing in a communal bucket.

Commercial Mask Defog is awesome!  It lasts years and years despite the small affordable 2oz bottle it comes in.  McNett Sea Drops and McNett Sea Gold are the best defogs we’ve used.  No bacteria or eye irritation and you also don’t have as much black mould or bacteria growing in your mask after 6-12 months of using it vs. spit.

Spitting in your mask is a good temporary solution, but defog will prevent things from growing in the mask and give you the best fog free solution.

To use your defog properly though follow these steps.

  1. Apply defog to mask lens dry 2-3 drops per lens or 5-6 drops overall if single lens max.
  2. Leave defog on the mask until you’re ready to hit the water
  3. Rinse defog off with your finger and water
  4. Put mask directly on your face or keep filled with water until ready to wear
  5. Keep mask on face, do not take off and let it air dry
  6. If taking mask off fill it up with water and leave lenses wet, don’t air dry

Maintenance For Your Mask

Your mask over time may get dirty, mildewed or saturated with salt crystals or sand which can get between the lenses.  Every 1-2 years or sooner, you should consider taking your mask apart and with hot water, some dish soap and a toothbrush, gently rinse and scrub every bit of the mask frame, skirt, lenses, and lens retainer clips (This isn’t possible with Frameless masks which do not come apart).

To learn more about care and maintenance of your scuba and snorkeling gear take our PADI Equipment Specialist Course.

In Closing,

The best mask on the market is the mask that makes you feel like its a part of your face, it fits naturally, it doesn’t hit off the brow, press on the bridge of the nose and doesn’t need to be overtightened.  It can come with a range of different lenses and price points, but at the end of the day its the mask that feels the best and has the features you want that’s the right one.

While technologies change, the fit criteria should all the same.  Comfort, ease of adjustment, ease of clearing because its low volume and it should look quasi-stylin’.

Matt Mandziuk
Recreational, Cave & Technical Diving Instructor
NAUI Cave & Trimix Instructor 45416
TDI Trimix Instructor 4767
PADI MSDT 207233
SDI Instructor 4767
IDREO Rebreather Instuctor (CCR)
Owner
Dan’s Dive Shop, Inc.
www.dansdiveshop.ca
[email protected]