Trelleborg products are found in a wide variety of contexts worldwide. They seal, damp and protect, both in everyday settings and under extreme conditions.

A Viking wearing a Viking: Robert Hedin, Commercial Diver

If, like my friend Rob, you are a commercial diver (or indeed a hazmat, military, fire & rescue or law-enforcement diver), then you will likely be intimately familiar with at least a couple of Trelleborg’s range of Viking Drysuits, as these are now the industry’s standard. They are impermeable, durable suits that can be used in a wide range of environmental conditions where there exist set standards for safety—they are extremely abrasion-resistant, will protect a diver from any contaminants in the water and can be easily washed down and decontaminated afterward.

If, on the other hand, you are simply diving for pleasure and not intending on exposing yourself to any toxic waste, you should still be aware of the existence of vulcanized rubber suits^*, particularly those with the Swedish Viking brand and specifically their old Sport and new ProVSN drysuits. The EPDM rubber of these suits is amazing stuff. If you cut one of the suits across its seam, you will see that there is actually no seam: the manufacturing process bonds the two separate layers so that they become one, which for you and I means… no leaks!

Viking Sport Drysuits

During the 1980’s Trelleborg introduced their Viking Sport drysuit, aimed at light technical and recreational divers. Although similar in appearance to their red and black commercial siblings, they are made from a lighter-weight rubber. These are no longer in production but can be purchased reasonably cheaply secondhand and, unlike crushed neoprene suits from the same era, will require little repair beyond new neck and wrist seals, if any, to get them back in action. Any repairs that you do need to make are as simple as patching the hole in the inner tube of your bike tire and can even be done hastily and temporarily in the field.

Viking ProVSN Drysuits

Towards the back end of 2009 Trelleborg released their new Viking ProVSN drysuit. I can’t say enough good things about these suits. The armatex nylon layers that sandwich the rubber central layer are stretchy and create a great-looking, comfortable suit that is available in front and back entry versions, with a variety of customisable features. Perhaps the only drawback of the suit is that the outer layer is permeable and so it is “problematic to decontaminate”—for most though, that is unlikely to be a problem.

What’s this about The Vulcans?

Vulcanization is a process best explained by someone else! So here is a link to a Google search: What the hell is vulcanized rubber?! The process makes rubber more durable and as far as a drysuits go this is great news; not only are vulcanized rubber suits incompressible (and so do not become less buoyant with depth) but they are also extremely hard wearing.

Who doesn’t like to see fellow human beings wearing rubber (or is that just me?)

I’m pretty good at answering the first question: “No, I haven’t. In fact, most sharks want nothing to do with me. I have to hold my breath and avoid eye contact just to get close to them”.

This often leads to a period of confusion and disbelief followed by a funny look of disappointment. Then they generally walk away nursing their shaken preconceptions. I can’t be sure but I think a lot of them are thinking; what does he know? He just photographs them. I’ve seen Jaws. This guy is an idiot.

The second question is vastly more difficult to answer because I have never been able to decide where the best place to go shark diving is.

It really depends on your expectations. Do you want to see lots of sharks or just big sharks? Great white shark encounters at Guadalupe Island, South Africa or Australia can be pretty amazing.

But, beyond Guadalupe there are so many outstanding shark dives. There is Cocos Island off the coast of Costa Rica where scalloped hammerheads school in their hundreds and where other omnipresent species like silky and Galapagos sharks cruise above every reef top. Then there is Tiger Beach in the Bahamas where tiger shark and lemon shark sightings are virtually guaranteed. Fish Rock in Australia is high up on many diver’s bucket list due to its colorful wobbegongs and squadrons of grey nurse sharks. And what about the whale shark spots at Ningaloo, Holbox, La Paz, Utila and elsewhere. There are also chumsicle feeds in the Bahamas, wild rides through the entrances of current swept South Pacific atolls packed with reef sharks and places where you can wrestle with an ocean full of spiny dogfish sharks. You see the problem. There are simply too many amazing choices.

I generally try to gauge my audience’s interest level before launching into a monologue about all the different encounters they could enjoy. Some people are just vaguely curious but others want to know all the details. If they really want to talk about sharks I don’t hold back. Sometimes I can see the excitement building behind their eyes. Those people walk away not just with information but with plans and if I can be the catalyst that leads to their first shark encounter then I will sleep well because I’ve never met a shark diver that didn’t want to help protect sharks and in the 21^st Century, sharks need all the help they can get.

Unfortunately, I can’t talk to everyone personally so if your interest is starting to peak I have one bit of advice; don’t worry about Jaws materializing out of the abyss at the first sign of blood, become a shark diver. Once you spend some time in the presence sharks you’ll soon develop a new appreciation of their intelligence and grace. And then after a few years (once you’re as addicted to shark diving as me) get back to me on that second question and tell me where the best place to dive with sharks is.

For the sharks,

Andy Murch

For DIR education, proper propulsion techniques are an essential part.  After a diver develops a solid base of buoyancy control along with body mechanics and trim, different propulsion techniques are added to the divers’ useful resources.  A collection of propulsion techniques will benefit the diver in many ways.  It does not take a new diver very long to appreciate the ability to swim efficiently forwards as well as backwards.  The menu of DIR propulsion techniques which are taught in the beginner Open Water/Recreational 1 level include a Proper and Modified Frog Kick for efficient and tireless motion, a Modified Flutter Kick for power, Backwards Kick for stability, positioning and control as well as 360 degree Helicopter-Turn.

When many divers swim they kick with their entire body.  The kick begins in their brain as they try to move themselves to another location.  The synapses fire and motion is generated in the leg, and the whole leg is involved with the kick.  Along with the calf, quads and glutes; the back, chest, shoulders and neck are also thrown into an explosion of muscle contractions in an attempt to generate movement.  Unfortunately, the return from all of this expense is usually wasted energy and CO2 build-up.  The answer is not to purchase easier kicking fins or build stronger muscles; it is to understand the muscles needed to generate propulsion.  We learn to use only the muscles that are efficient and productive; disregarding the inefficient and wasteful movements. It is important to develop a controlled use of the smallest and most efficient muscles through muscular compartmentalization of the body.  Instead of using the entire leg to kick, we learn to use only the muscles we need to use.

Any DIR class that teaches these essential skills will include a thorough understanding of proper propulsion techniques.  These skills are the building blocks for future development and their importance cannot be understated.  Along with proper body mechanics, buoyancy control, trim and technique, the propulsion techniques you develop in your DIR training will take your diving to a new depth of skill and ability.

For more information on developing these and other DIR techniques look into the UTD Essentials or Intro To Tech classes.

www.unifiedteamdiving.com

Or contact James Mott at

jm@unifiedteamdiving.com

The south side of the island is out of bounds to visitors , but supposedly open to study etc. The idea being that the island can remain as much as possible a marine sanctuary. The rangers that live on the island are very vigilant and an excellent job, tough as it is.

Apart from Bajo, the dive sites at Cano are between 30 and 60 ft (9 and 18m) , rock reef ridges with sand patches and coral spread out as far as you can see. One thing you are pretty much guaranteed to see when visiting Cano island is sharks. At almost every dive site you will find white tip reef sites lounging around on the sand patches.  This is what draws so many people to the island. They are always photogenic and as long as you practice good buoyancy, (which is a must rule for any diver in general) they will allow you a slow approach and snapshot.  One of the best memories to keep I think….you and one of the most beautiful creatures underwater.

One of the most popular snorkel spots  is a lesser visited dive spot, El Jardin. Translated as the garden, which when you visit it you will see why. The general depth of this dive sit is 25 – 45 ft hence the popularity for snorkelers. Spread out as far as you can see is some of the most beautiful hard coral formations that I have seen.   Whilst Costa Rica does not have the soft coral forests of the indo-pacific and caribbean the garden of hard coral, different yellows and browns does look impressive. It is also home to many cleaning stations for all the different species of fish. WIth the dive being so shallow we can extend our dive time and just cruise through the garden, watching all the interactions between different creatures and fish, fascinating. On my trip there last week as we came up for our safety stop, we were given the extra treat of coming across three green turtles, checking out the bottom and feeding. The safety stop extended to around 10 minutes as we hovered above them watching. Another rare treat from Cano Island!

Thank you!

Most rebreathers fall under the CCR category which in its self can be split further into two sub categories – Mechanical Closed Circuit Rebreathers (MCCR) or Electronic Closed Circuit Rebreathers (ECCR). The reason for these two sub-categories is mainly due to the fact that some people do not trust their life to a unit controlled by an electrical technology well underwater, others like me “trust the technology” and use an ECCR.

MCCR’s uses a mechanical valve of some type to feed a set controlled amount of O2 into the unit, such units as the KISS and the rEvo use this method. The ECCR has a solenoid that controls the exact amount of O2 required to maintain a preselected amount of O2 in the unit, such units as the Inspiration and the Optima use this method. The objective is to match the amount of O2 being supplied to roughly the amount the diver will or metabolise during a dive and both methods roughly attempt to do this.

The newer models of CCR units now come with a built in dive computer that will dynamical sample the O2 in the breathing loop of the unit and adjust the decompression obligation of the dive to reflect this amount, giving what is basically the optimum Nitrox mix for the entire dive.
CCR units are quiet and give the diver an unprecedented look at the wild life, no bubbles to scare them away, they also offer a much longer bottom time and a shorter decompression time for the dive. The units do though require advance training in their use and require a higher level of basic maintenance to be carried out. They also are more expensive to buy than OC gear and do have a higher cost per dive due to the consumables like CO2 sorbent and O2 sensor cells.

Given all the above I am still firmly of the view that a walk on the dark side will convert you to this new technology fully and unless you wish to spoil your OC diving for ever you should be avoid the temptation at all cost, once you cross the line there is no return.

All the air added should be there solely to equalize the compression that occurs with increased depth – the diver is equalizing the airspace inside the suit in order to remain comfortable and warm.

Additional adjustments may be required for buoyancy control and these should be made by adding air to or subtracting air from… the Buoyancy Control Device (whether that is a traditional BCD or a bladder/wing).

Drysuits should not be used for buoyancy control – they are suits that keep you dry whilst Buoyancy Control Devices, well, they are just that.

How many more bad pictures of bluespotted rays do we need?

The last few years the prices for under water housings for cameras has dropped like a dumped weight belt at the same time as digital cameras has become everyone’s toy. I’m not sure if this is a blessing or a curse. All of the sudden the majority of divers coming to dive the Red Sea carry a digital camera with an under water housing. Some small pocket cameras some big semi-pro cameras and most of them first time users that bought their photo equipment just before leaving for this holiday. Now, I don’t say that there is anything wrong with the desire to document a holiday, nor feeling the need to get a new approach to diving by picking up U/W photography. However, divers bringing photo equipment are likely to be the main reason we see so many broken corals when we dive.

It seems like the moment you put a camera in the hands of a diver is the

How many more bad pictures of parrotfish do we need?

moment he forgets the half metre extension of his feet, everything he ever learned regarding buoyancy control and the ability to listen to good advice. Dive centres rent out camera equipment to the left and to the right with no other advice than how to take care of the camera. Not a word about taking care of the reef. Divers of course have the same desire, and right, to document their holidays as the next bird watcher. Every one wants to show friends and family pictures from their trip to Egypt when they get back home. Especially if you have done something as exciting as scuba diving! On land this is hardly ever a problem. You take a photo of the pyramids or the sphinx, no harm done. Under water the situation is different.

You have delicate marine life that might have taken centuries to grow that can be destroyed in a jiffy by the smack of a fin or a thump of a knee. I have seen it so many times; the side of the reef getting both figuratively and literally scraped clean by divers with cameras that I’m actually surprised that we still have any soft corals left on reefs like Brother Islands or Elphinstone.

But it’s not only the reefs that are in danger. I’ve seen divers with cameras follow sharks out in the blue, way too deep or up to fast to get the “digital evidence” they need, risking to get swept away by the current, get bent or agitate the shark to a point on the brink of a leave-me-alone-nibble. Add some nitrogen narcosis to this equation and you have a potentially dangerous situation.

How many more bad pictures of masked butterfly fish do we need?

Some sea creatures get stressed easier than others, the carefree turtle for example, and the laidback dugong. They seem easily choreographed and willing to pose for the photographer but the reality is that they easily get stressed and might suffer mental and physical injuries if approached in the wrong way. This doesn’t necessarily mean that the diver is stupid or a bad diver, just that he is distracted or preoccupied with his camera.

When buying an under water camera equipment it’s easy to think “it’s a harmless camera that can hurt no one” and we have all heard the expression “leave nothing but bubbles, take nothing but pictures” as a way to describe environmental awareness. It might be time to change the second half of that expression. The truth is that a camera is not as harmless as one might think. It can make you, unwillingly, take unnecessary risks and make you damage the very marine life you love, what made you take up diving in the first place.

There are diving photographers and there are picture snapping divers. The photographers know how to compose a picture and how to get a good result. Also they are cautious and alert, not to add to the bad reputation under water photographers already have. The picture snapping divers have no idea how to create a good photo and they return home with hundreds of crap pictures of fish swimming away taken from above. In pursuit of these earthly useless pictures they often tear down the reefs like bulldozers.

A lot of divers are now also upgrading to their “second generation” of camera

How many more bad pictures of goatfish do we need?

equipment. This means that many people who finally got used to diving with a compact camera in a small housing have to start all over again. This time it’s a NIKON D70 in an IKELITE housing and two big strobes. All of the sudden they have to think about shutter speed and aperture. And… oups… the subject left already… The strobe-arms are sticking out scraping soft corals off the overhang. The water resistance increases and the air-consumption skyrockets… And… oups… no air for safety stop…

I’ve also noted that the enjoyment factor of the dive often fades as soon as the diver brings a camera. Often they get out of the water saying they weren’t pleased about the dive and that there was nothing to see. Simultaneously other divers go into raptures over how fantastic an experience it was. Most of the time, the reason is that you miss a lot of what’s going on around you, if you spend the entire dive looking through a view finder.

When I used to teach U/W Photo courses I always started with the sentence “Today we’ll learn how to avoid taking the crap ones” and I think this is one of the most vital piece advice dive guides and instructors can give to guests who come to dive with camera equipment. Don’t take the crap photos! If you concentrate on getting only the nice shots and plan your photo dives, you would probably spare the reefs immensely. And you would actually learn how to get nice shots rather than just keep the “not so bad ones” out of a few hundred bad. Instead of picking on the divers after the dive for the mistakes they did during the dive, try to come up with hints and tips before the dive. Here I would like to quote my friend Kimmo Hagman, one of the old-school-photographers who lives by the rule; “If you can’t get the photo hovering, don’t try to take it.”

At the end of the day I think the task lands in the lap of the dive guides and dive centres to advise and teach divers with cameras to remember to respect the marine life. To create rules and enforce them. Take our responsibility when renting out under water cameras and include environmental aspects in the pre dive camera briefing. And why not offer a course in underwater photography combined with peak performance buoyancy?

In the Red Sea we ask our guests not to use gloves to avoid damaging the corals but can we really ask them not to bring their brand spanking new camera equipment? Of course we can, and I think it’s our duty to do so if we see that the diver can’t dive sensibly. Or we might loose the beauty of the reefs and the very source and motivation of the dive industry.

Anders Samaka Jälmsjö
Diver – Philosopher – Nagging Old Man

The problem arises from a potential miscalculation on the part of researchers. Fisheries surveys conducted along the eastern seaboard of the US some years ago, indicated that although there were quite a few dogfish still at large, almost all of them were male. This led to fears that the population was heading for a crash and strict catch limits were put in place.
Again according to the fishermen, the survey was misleading and the leniency afforded to dogfish has led to a population explosion relative to other species. The dogfishes’ omnivorous appetite is now decimating the remaining fish stocks from New England to the Carolinas.
That sounds pretty bad but lets not dust off the long-lines just yet. Firstly, I’d like to see some concrete empirical evidence that all these anecdotal reports of marauding dogfish are true. Secondly even if they are, spiny dogfish are pack hunters. Swarming over the seabed like locusts is part of their natural behavior. Although I wasn’t around to witness diving in the good old days, I’ve heard some fantastic reports from British Columbian scuba divers that were active in the 1980s. Campfire tales of a wall of dogfish sweeping over the seafloor like the sandstorm scene from The Mummy. What a glorious site that must have been to be swimming along looking for Giant Pacific Octopuses on the reef and suddenly be engulfed in a tumbling maelstrom of meter long sharks.

The problems that the east coast fishermen are currently facing, speaks volumes about the sad state of our oceans in general. Where are the larger sharks that should be preying on spiny dogfish? And how did the ground fish and lobster stocks get so depleted that a school of dogfish can pose such an enormous threat?

Culling sharks to save the fish reminds me of the sophistical justification behind the controversial harp seal hunt. They’re looking at the problem backwards. If you want the fish stocks to recover, don’t kill the sharks, kill the fishermen.

Down Rambo! I don’t mean that literally. But perhaps a moratorium on depleted fish stocks would be a better way to handle the dogfish problem. How about we quit playing god and leave the oceans alone for a while to find their own balance.

Incidentally, BC is still a great place to dive with spiny dogfish. They are nowhere near as common as they used to be but a drift dive along the beautiful strawberry anemone covered walls around Quadra Island will still yield a handful of curious dogfish.

For further information contact
Abyssal Divers: http://www.abyssal.com.
Read more about spiny dogfish sharks on Elasmodiver: http://www.elasmodiver.com/spiny_dogfish.htm

What exactly is the goal of leaving some air in our tanks?  To help a buddy in need, to keep water out of our tanks, to inflate our BCD’s at the surface?  Many divers use the 1/3’s rule, but even this plan has numerous flaws.  So where do we start?  Is there a plan that works for deep-diving technical divers and shallow-water recreational divers alike?  What is wrong with the idea of surfacing with a safe amount of gas, like 500psi?

The answer to the 500psi problem is that being on the surface at the end of the dive with 500psi does not answer the more important question for scuba divers, which is, “When do I have to leave the bottom?  If we have an emergency and we need to share air, “How much air will I need to bring me and my buddy to the surface safely?  This is the question that should start all gas planning.

DIR education teaches the unified team to plan for the worst possible emergency before the dive starts.  We always ask the question, “What happens if at the worst possible moment, the deepest part of the dive, the furthest distance from home… my buddy runs out of air… How much gas do I need to bring both of us to the surface without any incident?”

Calculating Rock Bottom is easy enough to do in your head before the dive and it is taught in all entry level DIR courses.  How long will the ascent take, multiplied by two divers, then by the average depth and then by a consumption rate, equals Rock Bottom. Once Rock Bottom is determined, the remainder of the useable gas is then divided into a logical plan.  Maybe it is a drift dive on a Caribbean reef where we can use everything. Maybe we are diving on a shipwreck in the Great Lakes and need to get back to the mooring line, or we might be doing a penetration on this shipwreck where we will need enough gas to get out of the wreck plus enough to get to the surface.  Different dives will require different gas plans, but Rock Bottom must always be accounted for, before the gas plan is made.  DIR education teaches the unified team to plan their gas in accordance for the specific dive, so that each diver can get the most fun possible out of their diving and still be safe.

Being at depth below Rock Bottom is irresponsible and will not give us enough air to safely ascend.  The only emergency underwater is running out of gas, everything else is just an inconvenience.  Once the out of gas diver is breathing again, we move from emergency to management.  Just because someone ran out of air, does not mean that we rush to the surface, exceed safe ascent rates, skip safety/deco stops, or anything else we know about safe diving protocols.  The only option is to remain calm, think, communicate and finish the dive.

For more information about Rock Bottom or other Gas Management Options, contact me at jm@unifiedteamdiving.com

www.unifiedteamdiving.com

James Mott

Over-weighted, the negatively buoyant student diver begins to grow more comfortable with the workings of a demand valve regulator.  It is from this kneeling position on the bottom of the pool that students are introduced to various skills necessary for learning to scuba dive.  DIR education is trying to change this behavior and enlighten new divers and instructors to the logic behind neutrally buoyant skill development.

For a student diver, the position of kneeling negatively buoyant on the bottom of the pool becomes a basic ready position.  Stable and rooted, the student learns to remove and replace their regulator and partially flood and clear their mask.  Eventually, more advanced skills are introduced like full mask clears, mask removal and replacement, air sharing, etc., all learned on the bottom of the pool, negative and upright.  Much like in martial arts, the ready position associates the body with comfort and control.  However, the diver is not in control and is only ready for sinking and falling.  In the three-dimensional world of scuba diving the only position of universal control is the prone, balanced, neutrally buoyant position.

Unfortunately, neutral buoyancy is a skill that is usually presented somewhere towards the middle or the end of a course.  Instead of being taught to associate neutral buoyancy with comfort, control and basic skills, new divers subconsciously fall into a head-up, knee down negative position every time they perform a skill.  This is why we see divers plummeting to the bottom while clearing their mask, clutching the mooring line with a death grip while making an ascent, kneeling in a cloud of silt while tying a reel or perched on top of brain coral while trying to take a picture.  The learning law of primacy tells us that we should start these new students the right way.  Start with a base of balance, buoyancy and positioning; on top of that we can build personal regulator and mask skills.

This is one of many ways where DIR education differs from traditional scuba training.  The law of primacy tells us that the first thing a student learns is the most remembered.  Subconsciously these are the natural responses that occur when we are forced to react to a situation underwater, where conscious decisions cease and instinct takes over.  DIR education introduces the student to the underwater world with neutral buoyancy, weighting, balance and positioning.  Through this building block approach the student then learns additional personal skills.  Regulator removal, recovery, mask clearing, mask removal and replacement, air-sharing, etc.… are all done while maintaining neutral buoyancy, with proper trim and body mechanics.

As the year 2009 comes to a close, the time to reexamine how we present underwater education is long overdue.  The law of primacy upholds the DIR educational model.  The building block approach not only gives the student a solid base to grow as a diver, but also reassures the student and instructor both that when faced with a problem underwater, whether it is a mask clear or an air share, subconscious instinct is to remain neutral, stay in trim, breathe regularly and solve the problem.

James Mott