Loop Leaks and Water Intrusion

Leaks are bad, no matter if they are in Congress or in your rebreather loop.  They are annoying and dangerous.
Prior to diving we should all use a check list and do our pre-dive checks, two of which are the “positive and negative” tests.  Their purpose is to detect system leaks  before entering the water.  We pressurize the loop for a positive test and draw a vacuum for a negative test.  We then look for changes in counter lung volume and or listen for hissing sounds.  If they deflate, inflate or hiss we suspect a leak.  If they hold pressure and are silent we say they passed and are safe to dive.
But, are they?  It is quite possible you have a leak that eludes this process.
The Mouthpiece
Probably the most common leak is from a split or torn mouthpiece.  It can also be quite difficult to find.  A tiny tear or hole in a mouthpiece can present quite the mystery.  The loop will pass positive and negative testing and seem fine. Then, during the dive you hear that ever so annoying “gurgling” sound.  You listen for bubbles and hear none.  You signal your buddy to check above you looking for leaks and he tells you there are none.  But you keep draining the water from your loop so it has to be coming from somewhere.  To further complicate things, the loop might only take in water on inhalation or when you tilt your head in a certain position.  You may look for the leak on every exposed part of your rig and not find it. 
So what Do You Do?
If you are getting water in your loop and cannot find the source, even after checking all of the prime suspects, change the mouthpiece, even if it looks good.  This will often solve the problem or at the very least eliminate the mouthpiece as its’ cause.  Sometimes the leak is so minuscule that only an exaggerated stretch, bend or twist will reveal the tear or pinhole.   
Sometimes the cause of the leak is not a tear or a pin hole.  Believe it or not, if your DSV or BOV is angled incorrectly it will cause the side of your mouth to twist open when you move in certain positions and allow water in.  This could potentially cascade into a very unpleasant event if it causes the loop to pop out of your mouth.  If you are fighting your loop to keep it in your mouth straight it needs to be adjusted to fit you properly.  Loosen the hose clamps and move it so it sits at the same angle as your mouth and does not pull up, down or sideways.  Of course be sure to retighten the hose clamps properly.
Loop Hoses
A small split in the crevices of a loop hose can be very difficult to find.  It may only leak when the hose is stretched or turned in a specific way.  All other times it may be fine.  Because of this it is important to perform a visual inspection of your hoses as part of your pre-dive ritual.  Do this when you check your mushroom or flapper valves by stretching the hose.  Look for cracks or splits in the crevices between the ridges and where they are clamped to anything (DSV, TEE Pieces etc.).    Anything suspect should be visually inspected and tested with a soapy water bubble test or by submersion.  Remember, this type of leak can easily pass your standard positive and negative testing, so while I am not suggesting it is something to be paranoid about, it is not something to ignore.  This is why I do not like hose covers.  They may look cool but can conceal dangerous leaks.  High quality loop hoses are quite robust and do not need covers.
Be wary of rubber sleeves covering loop hose clamps.  They make the loop look pretty but they can conceal a large tear.  In the image below the loop hose was torn by the clamp but it passed a positive and negative test because the clamp was covered with a rubber sleeve which in effect, sealed the leak.
Should you find yourself in the water with this type of leak, the safest solution is to bail out.  If that is not practical or possible, an alternate solution is to grasp the hose with both hands and hold it in a position where it doesn’t leak, IE, press the offending crevice together to stop the leak while you abort the dive.  Obviously, this is only practical in a limited number of circumstances where the split is small and in which staying on the loop is a better choice than bailing out.  Remember, a flooded loop can lead to a caustic cocktail and cascade into a series of very unpleasant, potentially fatal events so if you make this choice, do so judiciously.
ORINGS
The next source of leaks and water intrusion are orings.  They should be inspected every time you build your unit.  Change any orings that have flat spots, nicks or cracks.  Lubricate any orings that require it but don’t over do it.  Remember that lube is also a dirt magnet so use care to not pick up any grit while the orings are exposed to the environment.  Also visually inspect oring grooves and clean any accumulated dirt or excess grease.  If necessary, remove the oring and clean the groove.  Use a plastic pick or something similar for removal to help prevent accidental damage.
DEWATERING
Every rebreather diver should be proficient at removing water from the loop.  He should also be cognizant of how water will collect in his particular rebreather so he does not do anything to worsen his situation.  For example, if you suspect water is in the unit and proximate to the scrubber you need to understand the unit well enough to avoid positions that will facilitate  water reaching the sorb.  I will not go into specifics here because every unit is different.  What works well on one unit might be bad on another.  If you do not understand this process well or if you understand it but are not good at it you should remedy this deficiency as soon as possible.  Practice the procedure often so it becomes second nature.  If you do not understand the path necessary to facilitate water removal, call your instructor and ask him to clarify it for you.  Once you thoroughly understand the flow of the unit, dewatering becomes very simple.  If your rebreather does not permit removing water from its breathing loop you need to account for that in your dive planning and factor in extra conservatism to account for it.  Avoid dives or situations where the probability of water ingress into the loop is higher than usual and access to the surface is limited.  You don’t want a flood 5000 feet back in a cave with no well rehearsed plan of escape.  Remember that a flooded unit becomes extremely negative, making swimming on open circuit bailout more difficult.  Even if you can no longer stay on the loop, the ability to remove water from it is important.
The Best Leak Test
 So, what is the best leak test?  At the beginning of every dive buddies should hover above one and other and look for bubbles.  The predive positive and negative tests will find any larger leaks but nothing surpasses an in water bubble check at depth to find any smaller leaks.  This can be accomplished at 20 feet in conjunction with a cell linearity check.  If this is not practical do it at depth before you begin the actual dive.  In any event, this should always be done.  Other indications of a leak include gurgling sounds in the loop, hissing noises behind your head, an unexpected change in buoyancy or an increase in the work of breathing.  The silence afforded us by diving a rebreather permits hearing the smallest of leaks so be acutely aware of any unusual sounds.  Do not ignore them.
I hope some of you, especially newer rebreather divers, find this information useful.
Until the next time, thank you for reading.
Joe
 
 

 

The Ring of Death

Over the years I have come to realize that in this sport we all love so much every diver is responsible for their own safety and well being.  The notion that anyone else will care about or protect you as well as you will do for yourself is flawed.  It won’t happen, which of course begs the question; how does one effectively ensure safety?

You Don’t Need A Crystal Ball

You need a little common sense which unfortunately, is often times not so common.  Most events having negative outcomes are usually highly predictable.  They have signs that are like billboards once we learn to recognize them.

Beware Of

Advanced tech dive trips or projects that are in search of participants.  They are always suspect.  If it is such a good trip or project why isn’t it filled?  The good ones fill up as fast as they are announced.  If the only requirement to get on an advanced Tech trip or participate in an advanced project is a certification card you should be wary.

Right about now you might be asking yourself, “Why is this so?”

Well, the answer is simple.  Tech trips and projects require larger numbers of qualified divers to make them viable.  By industry standards the only requirement is that participants hold the appropriate certifications which of course say nothing about experience levels.  It is only the level of human decency the organizers may or may not have that dictate how well they vet participating divers.  A well organized, safely run trip or project will always incorporate some sort of vetting process before divers who are unknown entities are allowed to participate.  Be happy when an organizer asks for a reference to vouch for you.  It means someone cares about the project or trip, you and your family.  They don’t want to make the phone call that all team leaders dread.

If you have no one to vouch for your abilities and experience level, DON’T LIE!  There are not that many participants at this level of diving.  Everyone knows everyone else and a good team leader will be able to vet you by who trained you and who you dive with.   You will fare much better by telling the truth and saying that you’d like to participate and would be happy to go on a benign “shakeout dive” to demonstrate your abilities.

It Works Both Ways

Just as trip and project organizers should vet you, it is in your best interests to vet them.  While anyone can have an accident or a bad day, if you pay attention you will find that whenever there is a negative event it is often the same people, places and operations that keep popping up.  Learn to recognize them and judiciously avoid the “Ring of Death”.   Don’t be afraid to question procedures and protocols.  Review their track record.  Is there a history of avoidable accidents?  Is there a history of incidents occurring because participants are diving past their experience levels?  If so, walk away.  If they don’t seem safe they probably aren’t.  The Wreck, Cave or whatever will be there for a long time.  There is nothing worth losing your life or your health to see there.

If It Sounds Stupid, It Probably Is

Learn to listen to that inner voice we all have and don’t be intimidated by someone who is vastly more experienced than you if the proposition sounds stupid.  You are probably right so don’t be afraid to ask questions and walk away if you don’t get satisfactory answers.  Often times there is a desperation to fill a boat or run a project dive and when the organizers can’t attract their “preferred” participants they open things up to anyone with a certification and dollars.  You might be tempted to think “Well I know I am experienced enough to do these dives so it’s not a problem for me”.  Well, it is unless you have no heart or soul.  I would like to believe that all of us would render assistance to a fellow diver in trouble even if we otherwise don’t know or even dislike the person.  By default this puts you in harms way.  The possibility of a panicked diver taking others to the hospital or grave is very real.  It is in your best interests to recognize that fact.  You don’t want to be surrounded by well meaning people who are diving beyond their experience levels.  If they have a problem you are most likely going to render aid and be in jeopardy.  The best option is to not be there.  Twice in my life I “dodged the bullet” this way.  Both times I was scheduled to go on a trip and when I heard who was going and what they were doing I suddenly had a scheduling conflict.  Both times there were fatalities.  My ego likes to believe had I been there those accidents would not have occurred; that I would have seen them coming and prevented them.   The realist in me knows that is not so.  You can’t save the world.

So, the next time you want to dive on a Tech trip or project, or do advanced dives with a group unknown to you, it is in your best interests to vet them first.  If all you need is a certification or the necessary dollars, run away.  If no one asks for your diving resume, run away.  If the operation or group has a dismal safety record, run away.  If you keep these “rules” in mind you will increase the odds of not being in or near the “Ring of Death” and enjoy many years of safe diving.

 

LIFT BAGS and SURFACE MARKER BUOYS

 

CLICK ON IMAGE TO PURCHASE

The origin of this post is a Facebook discussion about lift bags.  After reading all of the varying methods and opinions, I decided to add my thoughts to the conversation.  Those thoughts are here in addition to a few things I did not post on Facebook because they were not germane to the conversation.  I hope newer divers and students will find this useful.

I give preference to 400′ reels with #36 line. The heavier line reduces the length to probably around 250′ or so but the trade off in durability is worth it.  I also avoid reels with complex mechanisms.  Spring loaded snaps, latches or locking mechanisms just add to the complexity of something that should be as simple as possible.  Don’t read this as a condemnation of any particular style of reel.  I just think that a spool in a well constructed frame controlled with a bolt is pretty much as safe and simple as it gets.

I always carry 2 reels and 2 bags or SMB’s (Surface Marker Buoys). I prefer one of each. My SMB’s always have enough lift to get me off the bottom in the event of a catastrophe.   They also have my name on them and the words “Diver Below” so boaters won’t think they are just lost floats.  You should not be able to pull an SMB under the surface once properly deployed.  If you can, get another one.  Bear in mind that while a lift bag may have more lift, an SMB has less drag in the water.  This will make a big difference in strong current.

My reels have bolt snaps tied to the bottom of the handle as opposed to the double enders they usually come with. This is to lessen the chance of losing them and to facilitate clipping a second reel to the bottom of the first reel should you encounter a current sheer (currents moving in opposite directions in the same column of water).  This will cause the bag to travel horizontally and if your deco is long and begins deep you will most likely be dragged past your first stops if you do not do this.

Bags are always deployed from the wreck, no matter how deep. If you wait until you are shallow to deploy the bag you will most likely be lost. Currents in South Florida are quite severe and it is not unusual to drift 5-6 miles or more on a long deco.

Whatever emergency signal protocol is decided on, communicating it with the Captain and crew is paramount. Every team and boat will usually have their own protocols.  If you don’t communicate which one you intend to use the probability of a problem increases exponentially.  Never assume the crew will recognize a certain color or type of bag as an emergency signal.  It and any associated nuances should be discussed in detail before the dive.  The crew should have a clear picture of what to look for.  My preference is to send up a second bag on an already deployed reel and bag combination.  Do this by clipping the second bag’s bolt snap to the already deployed line and putting air in it.  Be sure to pull the line taut and the bag will rise to the surface easily and quickly.  There can be no mistaking this signal which is why I prefer it.

Re spools – they are great navigational tools but they are not appropriate for deploying a lift bag from depth. They are the wrong tool for the job. I’m not saying it can’t be done, but a simple reel is much easier to manage.

I clip my reels and bags to a D-Ring that is easily accessible and hopefully minimizes their impact on trim. Wherever stowed, I need to be able to access it easily and quickly. I also try to anticipate my needs.  If deep and in a raging current I want to have the second reel ready to attach to the first in the event a current sheer drags the bag or SMB horizontally.  I always deploy with my back to the current and in a position that will clear the wrecks superstructure.

I also use the bag / SMB as a tool to take me to my first stop as opposed to allowing the reel to play out and then begin the task of unnecessarily reeling in line. To do this I deploy the bag and when it gains velocity I lock up the spinning reel with my hand over the spool (never use the lock down screw for this – it needs to be very easy to release). I have the reel in one hand and my inflator in the other and when I approach my first stop I release the reel and dump gas. I can stop immediately using this method.

Deployment of a lift bag or SMB on a deep dive can be extremely hazardous if done incorrectly.  While there are several acceptable methods what is most critical is to minimize the risk of entanglement.  First, your back must be to the current so any potentially loose line will drift away from you.  If you are not sure which way that might be, release a few feet of line and see which way it drifts.  Turn so it drifts away from you and your back will be to the current.

When you are ready to deploy the bag it is best to be horizontal.  This minimizes the risk of entanglement because there is a smaller area exposed to the ascending line.  My preferred method is to get horizontal and secure the bag to the reel.  Then unlock the reel and let the bag drop 5-10 feet below you.  Next lock the reel and drop it while bringing the bag back up.  You are now horizontal with the bag  in hand and in front of you and with the reel dangling a few feet below.  Holding the bag away from your body put just enough gas in it to make it buoyant.  You should be able to hold it in place similar to a kids helium balloon if necessary.  When ready, release the bag while “OK’ing” the line and when the reel rises to your hand release the spool locking bolt and deploy as you would normally.  This method minimizes the risk of entanglement.

If you have a buddy with you the 2 man method is safest.  The man with the bag puts his back to the current and gets to the side and a bit above the man with the reel.  When ready, the man with the reel signals the man with the bag to deploy it.  When he does so the bag will rise above and away from both divers ensuring there will be no entanglements.

When working a reel anywhere, but especially in high flow situations it is very important to keep the line taut at all times.  If you allow it to go limp it can easily wrap itself around you, a potentially dangerous and at the very least embarrassing situation.

Lift bag skills are very important to the technical diver.  Often, divers are shy about deploying them because they don’t do it enough.  Don’t be.  That bag can save your life not only as a marker buoy but as an alternate form of flotation.  BC’s and Wings can fail.  Dry suits can blow gas out the neck seal and can be unwieldy as your only form of flotation.  A diver skilled in the use of a lift bag can get himself safely to the surface using it alone or in combination with a failed Wing / BC or dry suit.  Consider it your “ace in the hole” or a get out of jail free card.

Why Manual? The Debate Goes On

“Regardless of where the ‘parachute’ is set, nobody has yet explained why this is anything other than a daft idea.”

The above quote was taken from a recent discussion on an internet dive forum about gradient factors.  As per the norm, it eventually morphed into a sub-discussion about about the benefits (or lack thereof) of diving an ECCR (Electronic Closed Circuit Rebreather) manually.  I considered joining the fray but then thought better of it. Having wasted time discussing topics with people who don’t want to hear what you have to say, I decided it would be more productive to write an article expressing my views.

For me … the concept of using the solenoid as a failsafe or parachute is for the express purpose of developing both muscle memory and an internal clock in your head.  This will eventually enable you to intuitively know when the solenoid is supposed to fire.  Contrary to the opinions of some, it is NOT because anyone believes the electronics are unreliable.

When I dive I often like to use a controller set point of 1.0 and maintain a 1.2 or 1.3 manually.  When I hear the solenoid fire I view it as the machine telling me “Hey, dummy!  Pay attention!”  To make it interesting I try to make a game out of it.  I like to see how long I can go without the solenoid firing.  In the spirit of “every dive is a training dive” I use this as a learning / teaching tool.  If the machine fails I will (hopefully) easily catch it because I have trained myself to be acutely aware of what is going on with my ppO2, all by making it a game rather than a “chore”.  Of course, when I have a “busy” dive, I use the solenoid and fully appreciate the convenience it brings to the table.  Interestingly, I also find that subconsciously I know about when I should hear it fire and have found myself reaching for the manual add O2 button at the same time the solenoid is doing its job.  This kind of validates the main purpose of the exercise.

For a seriously deep dive I favor not using the solenoid at depth.  My preference is to dial it back to a safe level that is well below the desired set point.  The idea is that it is far less likely to stick in the open position if it is not opening and closing.  Also, remembering that it is not necessary to add O2 on descent, if you use the correct diluent, you should be close to your desired set point once you reach target depth.  My rationale is that a stuck open solenoid at say 5 – 600 feet is quite serious and its risk should be minimized.  I mitigate that risk by using the proper diluent gas for the dive; one that gives me an acceptable ppO2 at depth, manually tweaking it when necessary.  I use the solenoid on ascent where a stuck open failure is not quite so serious and much easier to manage.

To those whose opinions differ and believe utilizing the electronics is the preferred way to dive I say fine.  I agree that the human hand on a button is no match for the precision with which todays modern controllers hold set point.  I just prefer to retain as much control over the unit as is reasonably possible.  If I were to buy a Ferrari or a Lamborghini I would want a manual transmission even if an automatic was available because I want to DRIVE the car, not the other way around.  In that same spirit, I want to DIVE my rebreather.

 

Eye On Fire

I recently read a Facebook post where someone reported a serious eye injury after using Dawn Dish Washing Liquid as a mask defog agent.  Now one might think that using dish washing soap as a defog agent is not the wisest choice but I assure you it is not as bad a choice as one might think when you compare it to commercially available products that we assume are safe.  Some time ago I was with a group of friends diving at Peacock Springs (now named Wes Skyles) State Park when this unexpected incident happened to me.

I was parked in the lot adjacent to Orange Grove Sink.  The plan was to swim the Grand Traverse (Orange Grove to Peacock, a 4000 foot plus swim).  After prepping gear on the tailgate of my truck I put Sea Drops in my mask.  Some how the cap on the squeeze bottle was knocked loose or removed and improperly replaced.   Somewhat annoyed with myself I spread the excess over the mask face plate an propped it over my forehead for the walk down to the water.  My intention was to thoroughly rinse the excess defog off at the water and proceed with my dive.

The Road To Hell Is Often Paved With Good Intentions.

As I walked to the waters edge the mask slipped from my forehead and somehow the Sea Drops covered face plate smacked my open eye and coated part of its surface with the Sea Drops gel.  Annoyed at my own stupidity I continued my walk to the water and immediately immersed my head with my eyes open and violently shook it sideways, back and forth and up and down in an attempt to wash the Sea Drops out of my eyes.  I then addressed the mask and washed the excess defog from it.  Everything felt fine and thinking nothing of it I began my dive.

About 800 – 900 feet into the cave my eye began to “itch”.  Thinking nothing of it I continued on to Challenge sink.  By that time my eye was getting progressively more distressed.  I surfaced in the sinkhole, removed my mask and tried to wash out my eye.  I also asked my dive buddies to look for a foreign object in the unlikely event I had somehow picked up something in the water when “rinsing” my eye earlier.  Nothing was found and washing my eye brought no relief.

“I gotta get out of here NOW!”….

was the only thing I remember saying to my dive buddies and I began to exit like a bull in a china shop, swimming most of the exit at maximum speed with my eyes closed.  It was beginning to feel like my eye was on fire and closing my eye was the only thing that brought any relief.

By the time I reached the steps the pain was quite severe and my only thoughts were thank God Peacock is shallow and I had no decompression obligation and to get to an emergency room as quickly as possible.  I tossed my gear in the back of my pickup and left it at Dive Outpost.  The owner, Cathy Lesh very graciously rendered first aid,  trying to irrigate the eye while giving us directions to the nearest ER.

After Being Driven At Warp Speed…

I arrived at the ER about 30 minutes later.  When the registration process began the only words out of my mouth were “I don’t have time for this.  I have a chemical burn in my eye.  If you can’t care for me immediately give me the name of another ER or a walk in clinic and I’ll go there.”

They immediately dropped everything and rushed me into the ER where a nurse irrigated my eye and began a cursory examination.  At some point a doctor came and examined my eye, spoke with the nurse and left.  The nurse advised that there were 3 layers of skin or membrane covering the eye and the Sea Drops had burned through 2 of them, hence the extreme pain.  She also advised that the ph of the chemical was unrealistically high and was surprised that a product designed for use near the eyes would have such a high ph.  She also said the ph of my eye was very high and that I could not leave until it was normal.  Three or four hours and six bags of normal saline irrigation (or whatever they were using) later and I was free to go but still in pain.  The Doctor gave me some Oxycontin to take for the pain and it didn’t even touch it.  Just for the record, I don’t even take aspirin so this stuff should have knocked me out and it had nil effect.

I knew I was not fit to drive back to south Florida so the next day I made my way to an eye doctor and planned on spending an extra day to recuperate.  The doctor examined me and said there would be some discomfort but no permanent damage and proceeded to cover the eye with a contact lens.  The pain left instantly.  I guess the exposure to the air exacerbated the pain and sealing it off with a contact lens gave relief.  I was then advised to wait a few days and make an appointment with a local doctor who would examine me again and remove the lens.

I Arrived Home Looking Like A Pirate…

with a patched eye but with no pain.  I scheduled an appointment with a local MD who reaffirmed there was no permanent damage to the eye and removed the contact lens.  When I commented about the extreme pain she stated that the eye was one of the two most pain sensitive areas of the body, the other being an unmentionable.

I filed a claim with my Dive Accident insurer and all of the medical expenses were covered completely but I was dismayed by the reply I got when I suggested a caution be published in their quarterly dive magazine.  It seemed that there was a greater concern for advertising dollars than there was for diver safety.

So, the take away from all of this is to never assume (as I did) that just because we think a product meets a certain expectation that it actually does.  While Sea Drops is a good product for its intended purpose, shame on me for assuming that a cursory rinse would mitigate any potential injury from direct contact with ones eye.  After all, it is manufactured for use near the eyes.

I hope this serves to make people aware of the potential dangers of ANY  chemical in the eye, no matter how benign we think it might be.