Great ideas in wreck diving: Part 1: The Jon line!

It’s a great day for diving.  You’re excited to see the reef you’ve read so much about in your dive magazines and finally, you’re on the dive boat and on your way.  The warm tropical sun is shining down on you, you’re well rested, well hydrated and you’ve got the echo of Bob Marley in your head from last night.  You descend with the group, and enjoy the superb visibility on the reef along with the 11 other divers in your group.  The divemaster signals for everyone to start your ascent so you pick up your inflator hose, look at your gauges and start up.  Up the anchor line you go, watching your accent rate indicator as you rise.  As you arrive at 15 feet to do you safety stop, because you’re a safe diver, you run into something that unfortunately reminds you of home; a HUGE TRAFFIC JAM!  There’s just not enough room for you at 15 feet with all the other divers trying to do the same thing.  You notice that there is a bit of a current so you don’t want to let go and drift away, nor do you want to do your stop too shallow or deep negating the purpose.  What do you do now?

This is probably something that you have experienced at least once, and possibly many times depending on where you dive and what operation you use.  The good news is that, like most things in diving, there’s a solution to this predicament.  Given excellent buoyancy control and low current, it’s possible to do your stop without hanging onto the accent line.  I’ve done a free-floating safety stop many times, however at certain times conditions don’t allow it.  Even divers with immaculate buoyancy skills encounter current and surge on the accent that makes a free-floating safety stop both difficult and unadvisable.  That’s where a Jon line comes in handy.

No, a Jon line is not where you wait to relieve yourself.  A Jon line is nothing more than a 6-12′ lead you use to give yourself a little room at that very important 15′ mark.  Instead of bumping and crowding the group at the proper depth, you take out your Jon line, attach it to the accent line, attach the other end to your BC, and fly like a kite in the breeze, safely away from the crowd.

Although commercially available Jon lines are available, in reality it’s nothing more than a lightweight dog leash.  I use a 10′ leash designed for a poodle or other small dog.  I keep it tucked in my cummerbund pocket, pre-attached to a small key loop on the inside.  And on the loose end, is the small brass snap.  I pull it out, loop it around the anchor line and snap it to itself and I’m all set.  I fly in the current like a kite on the beach, comfortably away from the crowd.  When your safety stop is over, you can pull yourself in, unsnap, stow your line and head to the boat.

Crowds aren’t the only reason to use a Jon line.  Often times, surge from wave action on the surface can get so severe that holding onto a bucking anchor line is all but impossible.  However your Jon line acts like a shock absorber, allowing you to comfortably stay at your desired depth, without being beaten up by what’s happening to the boat.

It’s important to note that you must still concentrate on good buoyancy control.  Although “attached” to the anchor line, the length of the line can potentially allow you do drift up or down outside of your desired depth, so one must still monitor their buoyancy and pay attention.  Another important note of safety is to not choose a line that’s too large for the job.  Not only will an oversized line make it hard to stow in your BC, but also it becomes more difficult to cut in an emergency.  All that is required is the smallest gauge leash in the pet store, something suitable for a small dog or even a cat (I’m still not sure why those exist).  Which brings us to our final point of safety; have a knife. When allowed by local regulation, you should always carry a knife on every dive, and especially when diving with a Jon line, should unsnapping your Jon line become difficult or impossible.

The Jon line was developed by technical wreck divers who encounter both heavy surge on distant offshore wrecks that make the anchor line buck wildly.  But more importantly, technical wreck divers often perform lengthy decompression stops, and having to hold onto a line for hours can be rather daunting, thus the Jon line was developed making these technical dives that much safer and enjoyable.  Although this type of diving is well out of the realm most of want to achieve, we can still adapt their great ingenuity and make our recreational dives just a little bit easier.

*As an added bonus, I have taken many great shots of jellyfish, schooling jacks, and bait balls while enjoying my hands free safety stop!

Scott Shenton

www.scottshenton.com

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Great article about the rescue divers working on the Costa Wreck! (curious gear choices)

RESCUE DIVERS ON THE COSTA CRUISE

I’m surprised to see that the rescue divers are wearing single tanks with Y valves, and standard masks (no communication units).  I’m guessing they use single cylinders for space considerations.  Take a look at the article, and share your impressions of the dive operation.  How would you gear up for an operation like this?

Upon first impression, I would use independent doubles (no manifold).  This would give me 100% redundancy, plus double the air supply for unknown complications.  I would use a full face mask with a communication unit, to allow me to communicate with surface support and the other divers, to help coordinate rescue efforts.  However, this is my impression, based on my very limited knowledge of the specifics.  I’m looking forward for more details about the rescue effort (hopefully a successful rescue!)

http://www.dailymail.co.uk/news/article-2087249/Costa-Concordia-cruise-ship-accident-Divers-reveal-mess-survivors-brave-escape.html

Italy’s newest wreck dive…

http://www.bbc.co.uk/news/world-europe-16564789

This is an awful accident, yet if you read the news about the rescue efforts, it is really interesting to consider the wreck diving techniques being used. Electricity, fuel spills, unstable structures and the strong likelyhood of the ship rolling even more.  Think about what is being done to keep the rescue divers safe.

Many of recreational diving’s best practices were inspired by the technical diving community. The safety stop, jon line, wreck reel and redundent air systems were all innovations born in the technical diving community. Perhaps its time for some info on these tools.

If anyone finds more info on the diving operation, post it up here. We could all learn something from this that will make our own recreational dives safer.

How do you get such sharp images underwater? Getting up close and personal with marine life!

This is a question that most new underwater photographers ask at some point.  It’s not at all uncommon to encounter an experienced and well accomplished topside photographer, new to underwater photography, sitting on the dive boat, scratching their head while reviewing their shots, wondering why all of their carefully composed shots are hazy, blue, and unsharp.

Things just don’t work underwater like they do above the waves.  You have to change your game plan.  However with a little knowledge of the physics involved in capturing images underwater and a few adjustments to your approach you can bring the color and sharpness back to your pictures.

 

 

 

 

 

 

Believe it or not this ray was only 12 inches from my camera, shot with an ultra wide 15mm lens.

 

Water absorbs light rather quickly, with the red end of the spectrum being lost first, leaving the blue wavelengths intact the longest, deepest and furthest.  This phenomenon is taught as part of basic diver education in reference to how divers experience colors while underwater.  The rule is that the deeper you go the more blue things will appear due to the lack or red light.  What many budding underwater photographers tend to overlook is the fact that this property of water is in effect both vertically and horizontally.  Just more of the visible spectrum is lost as you go deeper; you lose the same light the further they are from your subject.   In order to see something, light must come from a source, hit the object and be reflected to your eyes.  So if one considers light from the sun, traveling 60 feet underwater, reflecting off of a fish or piece of coral, and traveling another 20 feet to the camera, it has had 80’ of water to absorb that light.  This makes for some pretty blue pictures!  With the use of a flash you can artificially cast a balanced spectrum of light on your subject giving you all that color back.   However, how and where to use that flash is its own topic, better addressed another day.

 

 

 

 

 

 

This is what happens when too much water is between you and your subject.  This manta was shot from about 10′ away with a 60mm lens.

 

Another thing to consider about the underwater environment is the effect that turbidity has on our pictures.  While using any sort of lens with a long focal length or “zoom” lens, you are artificially bringing the image closer to the camera, or in other words, “compressing” the distance between you and your subject.  However you are also compressing everything that is between you and your subject.  In air with its high degree of visibility, the effect is negligible.  However while underwater, all of the little suspended particles and plankton that are invariably in the water column are also being concentrated onto your picture.  The result is poorly rendered, and softly focused pictures.   To use a long focal length lens underwater similar zooming in on a topside subject through a long distance of thick fog.  The only way to get a sharp image is have as little water as possible between your lens and your subject.

So what is an underwater photographer to do?

Get close.  Get REAL close!  This is the only way to get crisp, clear, and most importantly colorful pictures.  Rarely does an underwater photographer use any lens longer than 35mm unless they’re shooting a macro lens with a specialized close focusing distance allowing a 1:1 subject/film ratio.  A vast majority of underwater pictures of relatively large subjects, say a fish or turtle, are taken with 24mm, 20mm, and even 15mm lenses and are shot from mere inches away.  For example, if you were to take a picture of your dive buddy on the beach, you would stand back 20-30 feet and zoom in to fill the frame with their body.  However to achieve similar sharpness and color while underwater, you would want to have your camera no more than 24” from their body.  This is where wide-angle lenses come in, because they allow you to get in close and still get your entire subject in the frame.  Additionally the shorter the focal length lens you use, the closer the workable focusing distance will be, and this further aides your ability to shoot in close.  Long zoom lenses may be popular on land, but they have no purpose underwater.  By eliminating excessive water, silt and plankton between you and your subject, you will be able to shoot pictures that are as crisp and colorful.   

 

 

 

 

 

 

This picture of a moray eel was taken no more than six inches from those teeth!

 

So what is the key difference between a great underwater photograph like you see in the magazines and one that you wouldn’t show to your family?  It’s not the top-of-the-line camera, not the exotic lenses, and not the artistic vision of the photographer.  It’s the ability to get close to the action.  Work on your buoyancy control; get good at estimating distance underwater, study up on the habits of your subjects and most of all is to be patient!  I’ve spent many dives awkwardly perched upside down for most of my no-decompression time waiting to get close enough to a subject to get a proper image.  In the end it’s always worth it!

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Tread Lightly: Ecotourism may not be as innocent as it seems

Despite our efforts to enjoy our planet’s ecosystems without having a negative impact, it’s become clear that ecotourism has the potential to be very harmful.  Although ecotourism is being advertised as being zero impact, it’s clear that the masses of people touring these ecosystems are taking their toll.  In light of this reality, it’s important that we address these problems before too much damage is caused by our seemingly innocent interest in our planet.

Ecotourism is unique in two main ways.  First, ecotourism concentrates on enjoying the natural splendor of our planet and largely avoids city centers and human accomplishments, and somewhat ironically as we will learn, it’s designed to be impact free, meaning that the visiting people do not damage or influence the environment during their visit.  Due to the massive popularity ecotourism has enjoyed over the last couple of decades and its subsequent expansion, the definition of the term “ecotourism” has evolved.  ”Ecotourism” now commonly refers to any tourism that centers itself around enjoying nature, and away from its original impact free designation.  It’s this new definition of term “ecotourism”, which will be the basis for our examination of the problem.

Many good things have come from the popularity of ecotourism.  Thanks to ecotourism, many of our planet’s environments are now well understood and in turn protected (at least in spirit) by a large portion of the world’s population.  Without this exposure, many of these places would have gone ignored or forgotten, leaving them exposed to industrial harm without any sort of politically organized opposition.  In addition, a lot of the revenue being produced by this brand of tourism is contributing to conservation efforts in host countries as they continue to recognize the benefits of their unique natural resources. Additionally, a lot of promotional material is being produced which highlights that ecotourism helps these environments by educating the public, generating funds for conservation and an increasing public interest in environmentalism.

Ironically, ecotourism is also causing harm to the ecosystems we travel to see.  During the First International Conference on Climate Change and Tourism held in Tunisia in 2003, it was noted that the various means of transportation these tourists are using to travel, are having a negative impact on the local environments.  The increased use of roads, airplanes, and ships has become a major contributor in the accumulation of greenhouse gasses, as well as noise pollution.  They also noted that while visiting these remote locations, people are consuming large amounts of water, food and other consumables.  This in turn increases the need for the importation of consumable products, as well as an increase in the need for drinking water and sewage treatment; all of which have a negative impact on these delicate environments.   The world’s coral reefs, grasslands, and rainforests are suffering from physical damage due to the increase of human traffic through these environments, which prior to the boom in ecotourism’s popularity, would have remained relatively untouched (at least by these masses of tourists).  It’s become clear that too much of a good thing, is causing ecotourism to become a foe instead of a friend of nature. 

To better understand the issue at hand, it’s important to look at a specific case where ecotourism has become an issue.  Costa Rica was an early pioneer in the formation and popularization of ecotourism.    Ecotourism first arrived in Costa Rica in the 1960s and quickly grew into a multi-million dollar business, and by the mid-nineties a vast majority of visitors were arriving in Costa Rica for nature related activities.  But despite the economic growth and social awareness that the Costa Rican government has managed to provide, many of the country’s fragile ecosystems are being threatened by over-visitation.  There has been a steady decline in numbers of rainforest birds as well as the quality of Costa Rica’s rivers and inland waters.  Many of these problems stem from the fact that there is little or no enforcement of any established standards of ecotourism.  Almost any travel company can provide “ecotourism” to their clientele, however very little of this “ecotravel” actually operates in an ecologically sustainable manner.  In order to provide tourism for the masses of travelers now wanting to spend their hard earned travel dollars to see nature, impact free travel have been replaced with methods that suit higher volume business.

This damage is not limited to land, it’s also occurring in the oceans.  Coral is a very delicate type of marine animal with a soft tissue that grows around a hard inner skeleton.  Over hundreds of years, this growth accumulates into the reefs so admired by tourists.  However it only takes a very slight touch to damage years of coral growth.  Unskilled divers and snorkelers alike will touch and kill portions of the reef because of their close proximity to the delicate coral.  Skillful divers can avoid contacting and damaging coral reefs through the use of good buoyancy control.   However with the increase of participants in such activities (due in large part to increasingly less stringent certification standards), also comes an increase in damage.   To that one must also consider the impact of the boats carrying these people to the reefs.  Anchors and anchor chains are claiming huge pieces of coral growth when used carelessly.  With an increase in number of tourists, comes an increase in the need for accommodations and services.  Costal habitat destruction has grown out of control in many of the world’s top reef destinations.  The mangrove forest, a vital part of the life cycle of reef animals is being removed to make room for hotels to accommodate reef-seeking tourists.  Not unlike other areas of the world, the use of fresh water and the production of wastewater in these destinations have also been on the rise.  

A coral reef is naturally a very nutrient poor environment.  Subsequently corals have adapted exotic means of nutrition in order to survive in such nutrient poor water.  They carry symbiotic algae called zooxanthellae which lives within the coral’s tissues and provides it with its beautiful colors.  However with the massive influx of nitrates and phosphates (two major bi-products of treating waste water), the ocean’s water chemistry is changing.  Corals are suffering from bleaching and are being choked off by invasive algae species competing for the same space on the reef.  This invasive algae, unlike corals, can utilize this chemical waste directly, thus allowing it overtake the coral reef in a race for survival.  In addition to these physical and biological threats, there are social threats to the reef environment as well.  With an increase of tourists comes an increase in the demand for shells, dried corals for souvenirs, as well as local cuisine such as fish and lobster.  When all of these factors are taken into consideration we get a clear picture on how badly coral reefs are being damaged by “nature friendly” tourists.

The heart of the problem is that the term “ecotourism” has lost its original meaning.  This misnomer gives tourists a false sense of environmental transparency.  If a tourist thinks its “ecotourism” it must be safe for the environment, right?   Well, not really.

 Over time people have taken the term ecotourism as a synonym for sustainable tourism.  In reality sustainable tourism is much more than just caring about the environments we visit.  Sustainable tourism must also take into consideration all factors that affect a specific ecosystem.  This is a level of awareness that few nations have achieved in there promotion of so-called ecotourism.   However with a better awareness of the problems associated with ecotourism and an increase in efforts being made by the hosting nations, it’s possible to return ecotourism to its environmentally friendly origins.  As of now, there are few worldwide bodies governing the promotion of ecotourism.  However recently the idea of an ecotourism oversight organization has become a popular concept with concerned activists.  Others suggest alternatives to a governing body, such as the promotion of eco-aware propaganda, educating people on the issues associated with ecotourism.  Either way, it’s clear that people are becoming aware of the need to control the growth of ecotourism.

Opponents to these changes will argue that enforcing standards to what can be sold as “ecotourism” will decrease travel volume, thus decrease the money that is coming into these nations.  This argument has a certain amount of merit, because it’s inevitable that fewer travelers will choose a truly sustainable tour, with its associated compromises in price, comfort and convenience.  However, if environmental stewardship is the true goal, fewer travelers are exactly what the doctor ordered.  With a decrease in the number of travelers, there will be inevitable rise in the cost of ecotourism.  In turn, this rise in cost will cause ecotourism to be somewhat self-limiting and ultimately that is a good thing.   What is agreed upon however is that ecotourism is not currently being practiced in a sustainable way and changes must be made, or all of our gains in awareness will be for nothing.  We will simple become acutely aware of the damage we are causing.

While ecotourism is considered by many people as being ecologically harmless, its popularity has turned it into one of the planet’s most devastating problems.   While these ecotourists travel to enjoy and preserve our planet’s most beautiful ecosystems, the sheer volume of people and the poor management of this booming industry have caused ecotourism to become a threat.  With a stronger set of ecologically sustainable standards as well as in increase in the education and awareness of tourists, it will be possible to turn ecotourism back into an environmentally friendly way to see the world.   I for one will continue to participate in ecotourism, but I also fully intend on adapting to the real world requirements, to keep my travel environmentally sustainable.  Even if that means higher prices and less air conditioning!
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An Argument for Dive Tables

Although dive computers are now considered an indispensable piece of equipment, they simply do not, and should not, replace the roll of tables in diver education.  Dive tables illustrate the physics behind decompression theory in a way that computers simply cannot.  Only with an adequate knowledge of the rules of safe diving, and more importantly why these rules exist, can any diver be expected to be self-sufficient underwater.

One of the first things that every student diver should learn is a law of physics called known as Boyle’s Law. Boyles Law states that the volume of a gas is directly relative to the  pressure applied to it.  In other words, if you increase pressure exerted on a gas, the volume of the gas decreases.  This is expressed as the gas’s partial pressure. Inversely, if you decrease the pressure exerted on a gas, the volume of the gas will increase, thus lowering its partial pressure.  Boyles Law affects gases in a free gaseous state, as well as gases dissolved within another substance.  When gases at a higher partial pressure come in contact with a substance at a lower partial pressure, they have a tendency to equalize.  That is to say  the higher-pressure gases will migrate to areas of lower partial pressure, until the partial pressures in each substance are equal.  When a diver enters the water, their body is put under pressure by the surrounding water. This pressure compresses the molecules in a diver’s breathing air, (primarily oxygen and nitrogen), allowing a greater amount (in mass) of these gases to dissolve into the body then possible at the surface, due to the gas’s reduced volume relative to its mass. However our body tissues can only hold a certain volume of these gases in a dissolved state.  This is not unlike a glass of water that can only hold a certain amount dissolved salt.  So it’s important for a diver to monitor “decompression status” to prevent exceeding this limit and causing a life threatening condition referred to as decompression sickness.

Unlike oxygen,  which is metabolized by the body, the nitrogen in our breathing air is inertand can’t be used by our body, so once absorbed it must leave the body the way it was introduced; by way of our respiration. If you decrease the pressure on a diver (ascending from a dive) you will increase the volume of the nitrogen dissolved in your tissues.  If the volume of that dissolved nitrogen exceeds the carrying capacity of your body, it will return to its gaseous state while still in your body, causing decompression sickness. 

To better illustrate this point, consider a can of soda. Carbon dioxide is dissolved into the soda at a high pressure.  When sealed in a can, that pressure remains  constant and the carbon dioxide remains dissolved.  However when you open the can, you are releasing that pressure.  The carbon dioxide expands, exceeds the carrying capacity of the soda and returns to its gaseous state, causing bubbles to form.   The same happens to a diver when they stay too long at depth.  Once they ascend and lower the pressure exerted on their bodies, the dissolved nitrogen in their tissues expands and can potentially exceed their body’s carrying capacity.  Therefore it’s important to monitor the time spent at certain depth/pressure by way of a dive table or dive computer to prevent too much nitrogen from dissolving into the body.

The first dive  tables were organized in 1906, by conducting simple decompression experiments on lab animals, and charting the results. Later, the United States Navy revised the tables and printed them for use by Navy and commercial divers.  Over the years the dive tables have evolved into increasingly more conservative models to accommodate recreational divers, however the principals behind them remain the same.

A basic dive table displays a list of depths on one axis, and a list of times on the other.  Additionally each depth is noted with a maximum time, known as the bottom time. This is the time (in theory) it takes to absorb the maximum amount of nitrogen that once returned to the surface, would not exceed the body’s capacity.  The deeper the depth on the table, the shorter the time allowed.  On the flip side of a dive table, is another chart allowing a diver to calculate needed information to perform multiple dives in succession.  The key benefit of these tables is that the diver must stop, think and take the time to work out their no decompression status in order to dive safely. 

A dive computer is an electronic device that tracks depth, time and decompression status automatically.  It uses the same mathematical models as found on a dive table, but does these calculations for the diver and presents them with a simple descending timer to guide them on their dive.  A diver simply activates the computer and follows the guidelines offered on the computers display.   Although convenient and accurate, it does not require the diver to actually understand the information given, it only requires them to obey it.  In recent years, dive computers have become so popular, that many training organizations now consider dive tables to be obsolete and are pushing to have tables eliminated from diver education altogether.  This would be a great loss to the industry.

In all fairness, dive computers are popular for a good reason.  They eliminate human error; allow for a more detailed dive profile, and they are easier to use than dive tables.  I use a computer on every dive I make.  Because of these benefits and their seeming universal popularity, some believe that teaching dive tables is now unnecessary.  However, I reject this philosophy and believe that the dive tables must remain a required part of diver training.   The fundamental knowledge of why a dive computer is telling a diver something is just as important to that diver’s safety as what the computer is telling them. 

As an example, if someone learns to drive a car and is simply told to “stop at red lights”, but is never explained why, it is likely that the first time they come up to a red light, they will ignore the rule and cause an accident.  However if that person was told to stop at the light, because there is cross traffic, that driver will likely stop, because they understand the reasoning behind the red light.  When diving, it’s important for your safety, as well as your enjoyment of the sport, to understand decompression theory, what a computer is for, why you should use it, and how it works.

Divers recreate in a hostile environment, and eliminating decompression theory from basic training, would be inviting disaster. For our sport to survive, grow, and remain relatively unregulated, we must insist that our fellow divers are conducting themselves in a safe, responsible manner, and the only way to insure that is to insist upon an adequate education.  Otherwise we are encouraging divers to blindly follow the advice of a digital display, taking no responsibility for their own safety and in the end, this can only damage our beloved sport.
Scott Shenton

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Here we go!!!

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