There are a lot of ways to stand out against the competition these days; and the good news is, it doesn’t mean you have to have the lowest prices. In a business like diving where there’s no shortage of dive retailers, you may often feel yourself stuggling to set yourself apart from others. There are many ways to stand out and we’re giving you some ideas on how to do it.
No matter what level of diver you are there’s one thing that stands true for all: buddy checks. The truth of it all the higher level of certification usually the more things can go wrong. It’s important that before every single dive you and your buddy go through a buddy check of each other. We’re giving you some guidelines on what you should be doing before every dive.
Over the last 10 years SDI/TDI/ERDI has seen tremendous growth throughout the world. Due to our growth outside of the United States, we recently decided to expand the staff working with Paul, by adding Jordan Greene, an experienced member of our staff, and Mark Powell, a long time IT for SDI/TDI/ERDI from the UK.
by Mark Powell
Good marketing is key to the success of any business. Most people would readily agree with this statement but it is surprising how much variation there is in what people think of as “marketing.” Before you read any further I want you to take a few seconds to think about what you understand of this term, “marketing.”
I would imagine that you thought this question would be relatively easy; after all, everyone knows what marketing is, right? In reality, it is one of those terms that everyone recognizes, but finds very hard to define. You can also try asking friends, colleagues, customers and staff the same question and see what responses they give. The answers will probably include some mixture of advertising, selling, customer needs, value, strategy, positioning or promotions.
Part of the reason for the range of answers is that marketing has changed over the years, and many people have definitions that come from different stages in it’s evolution.
In the 1950’s and 60’s, there was not a huge variety or availability of products. Put simply, customers bought the products that were available, and so marketing was associated with selling. We can call this the Marketing=Selling period. Marketing involved selling the products that a company made. As a result, marketing was a sales support function involving advertising the product to the consumer, setting a competitive price and having effective salespeople.
In the 1970’s and early 80’s, a wider proliferation of products, increased technology and competition from countries such as Japan, Taiwan and Korea changed the way customers looked at products. This required a more sophisticated approach to marketing with more focus on effective promotions and market research. During this period, marketing communications developed as a way to better get the message to the customer. Sales techniques became more sophisticated and this led to a phase referred to as the Marketing=Selling+ period.
In the late 1980’s and into the early 90’s, the focus shifted from products that the company was producing to products that the customer wanted to buy. This led to a major shift in the way marketing was viewed, and more market-focused companies, rather than product-focused. Rather than trying to convince the customer they wanted to buy the products that had been developed by the company, marketing was used to help design products that would appeal to customers. We can refer to this as the Marketing=Accepted Philosophy approach.
In the 1990’s and into 2000, this approach was developed further so that marketing influenced not just the product development process, but the whole approach of the company. In this way, marketing became one of the key tools for strategic planning. Companies were driven by the requirements of the market and specifically by meeting the needs of customers. The aim was to develop a superior value proposition for the customer by focusing not just on the product, but also on the service provided to the customer and the image of the company. This is known as the Marketing=Driving Philosophy period.
So it is no wonder that marketing has many meanings to different people. It has been used to in very different ways; from a slightly more sophisticated way to sell products, to the driving philosophy of a company’s strategy. Your answer to the question, “what is marketing?” asked at the start of this article will give an indication as to which period of marketing you are thinking of.
This history lesson in the development of marketing might be very interesting from an academic point of view, but how is it important to a scuba diving instructor or dive centre owner?
The fact is, the diving industry has gone though a very similar process. At the start of our industry, diving instruction and products were very rare and were desperately sought out by those who wanted to become scuba divers. Scuba diving was new, innovative and exciting. Customers were desperate to buy the product, and so the only marketing required was to make sure the eager customer knew where you were. This is the equivalent of the Marketing=Selling period. As the number of instructors and products increased, and professional agencies developed well structured programs, it became more important to differentiate yourself from other instructors, centres and products. During this phase, the Marketing=Selling+ approach worked well.
As scuba diving became more established, and other adventurous pastimes became more popular, instructors, dive centres and scuba equipment manufacturers had to focus more on identifying and meeting the customer’s needs. More tailored programmes were introduced, as well as a range of equipment to suit different needs. This shows how the industry had moved into the Marketing=Accepted Philosophy period.
Today many divers are also regular mountain bikers, skiers and social activists, as well as family members and business people with time and financial commitments. Providing a service that suits and appeals to these customers is a much bigger challenge than in the past, and one that can only be achieved by adopting a Marketing=Driving Philosophy approach. If your view of marketing is stuck in one of the previous periods, then your business is at risk from the competitor down the street who is offering what the customers really want, presented in a way that appeals to them, and structured in a way that is consistent with their other commitments. On the other hand, if you adopt a Marketing=Driving Philosophy approach you can develop and grow a strong business which matches the requirements of your customers. This approach will also allow you to adapt to their changing demands and to the social, technological and political factors that affect the diving industry.
Mark Powell is a SDI/TDI Instructor Trainer, consultant to the diving industry and the author of Deco For Divers. Prior to becoming employed full time in the diving industry, Mark was a visiting lecturer at the London School of Business and Management after serving in a range of international sales and marketing management roles.
by Mark Powell
One of the most important techniques in marketing is the concept of segmentation, targeting and positioning (STP). These three tools allow businesses to identify their most likely customers and tailor messages to these customers in order to increase their chances of offering the right product to the right customer.
Segmentation is the process of splitting up a huge group of all possible customers into meaningful sub groups. Segmentation is often done on demographic lines such as age, gender, income levels, family size, home address or work address. For example, a business may split its customers into male and female customers or into customers that are in their teens, 20-30, 30-40, 40-50 and over 50. Alternatively, a business may distinguish between customers that live within 10 miles of their store and those that live more than 10 miles from the store. In addition to these objective demographic categories, segmentation can also be carried out on a more subjective level, such as life stage, personality or behavioural characteristics. For example, life stages might include single, married with no kids, married with young children, etc. Although there is a correlation with age it is not fixed. For example a married couple in their forties may have no children, one young child or two teenage children. The key point of segmentation is to pick segmentation criteria that are relevant to the product or service you are offering.
Once you have chosen your segmentation criteria, the next step is to select various segmentation groups to target. For example in the video games market, age and gender are commonly used for segmentation. Early targeting strategies focused on males in their teens and early twenties. As a result games were developed that appealed to this target group. However, as the industry developed it was realized that there were other potential target groups. Older customers from both genders were targeted for a completely new genre of games involving brain training and female customers in their 30s and 40s were targeted for games such as the Sims and Farmville. By the use of suitable segmentation criteria, the games industry was able to hugely increase its potential market. It is only by the use of segmentation and targeting that this was possible. If they had tried to offer the same product to all groups they would have failed to expand beyond their initial market, however by realising that there were different segmentation groups the industry could offer a more suitable product to each of those groups.
This third stage is known as positioning. This involves offering a product that suits the target group and communicating with that target group in a suitable manner. In the video game example, positioning started with offering a radically different product to each target group. In other cases the same or very similar products can be positioned very differently by means of packaging and advertising. A good example of this is Diet Coke and Coke Zero. What is the difference between these two products? There are some minor differences in the recipe but ultimately they are almost identical in terms of the actual product. The real difference is that Diet Coke is aimed at women and Coke Zero is aimed at men. As a result, the product packaging for the two is very different and if you have ever seen a Diet Coke advert it is obvious that it is aimed at women while Coke Zero adverts are clearly aimed at younger men. In this way Coke can position their product specifically for the relevant target markets. Trying to come up with an advert that appealed to both men and women would be much less effective overall.
Positioning your scuba diving courses will also depend on your target group. One target group may prefer online training while another may prefer the face to face approach. One group may be attracted by action and adventure while another may be worried about the risks involved. One group may be interested in marine life and the environment while another may be more interested in exploring wrecks. One group may be interested in diving in far flung exotic places, while another maybe more interested in being able to train locally without the need to travel away from home. By coming up with an appropriate set of target groups you can put together a set of offerings that appeal to those target groups.
As well as product specification and product imagery, positioning can also affect your choice of advertising medium. National TV advertising on a major channel can have a huge reach but is a very expensive and an inefficient method of reaching a specific target group. If your target market lives within 10 miles of your dive centre then local advertising will be much more cost effective than national advertising. If you are targeting new divers, diving magazines or online forums are not the right place to look for those customers. However, if you are targeting experienced divers who are looking to get into technical diving then they are much more appropriate. If you are targeting inexperienced divers who want to gain more experience then your open water students over the last few years are the best starting point.
Segmentation, targeting and positioning is not a magic bullet but if used correctly it can help any business owner identify likely groups of potential customers and help you think about how best to position your offering to those customers.
by Mark Powell
Why do divers do stupid things? Well the short answer is because they are stupid. Now I know that the majority of the readers of this article are going to be divers and it’s not usually a good idea to start off by insulting your audience but bear with me. If you look at some of the recent diving incidents that have occurred such as the tragic double fatality of a father and son who died while cave diving on Christmas day, or the diver who refused to analyse his gas an ended up breathing 100% oxygen at 30m or the rebreather diver who jumped in with oxygen, diluent and handsets all turned off then you can see why I might say that. The British Sub Aqua Club publish a summary of diving incidents every year and a brief glance at this will show that dives do a whole range of stupid things. Not only that but they do the same stupid things over and over again. Most of the mistakes made each year are the same as the mistakes made the previous year. The short answer is that divers do not follow their training. It would be very easy to stop the vast majority of diving accidents if we could just force divers to follow their training. If you do what your instructor taught you during your course then you will avoid the vast majority of problems that occur. The thing is that you already know that, I know that, everyone knows that and yet hundreds of divers every day do things that break what they were taught in their training.
Is this because divers are genuinely stupid? or is it because they just act as if they are stupid? I believe that divers do stupid things because they are human and humans make mistakes. However that doesn’t mean that mistakes are inevitable. If we understand why we make mistakes we can potentially avoid them. If we recognise that each and every diver has the potential to make mistakes then maybe we will be a little more careful and a little less complacent.
We all have the potential to do stupid things because we sometimes get complacent, because we rush, because we are not very good at assessing risks, because we are often over optimistic. We do not always call a dive when we should, letting multiple little problems build up until they become a major incident. We trust our own powers of observation and can easily get fooled into trying to solve the wrong problem. Finally we often let other people influence us unduly.
I have tried to bring some of these ideas together and have given a number of talks on this topic at dive shows throughout Europe and the US. The video above was shot at TekDiveUSA (www.tekdiveusa.com) in Florida recently. This conference brought together technical divers from all over the world to discuss exploration, diving medicine and diving safety. As part of the conference I was asked to put together a short film which summarised why divers do stupid things. I hope this film helps explain why there is always a risk that we might do something stupid and hopefully will help you to avoid doing anything stupid in the future.
By Mark Powell
The image that many technical divers try to promote is that they are tough, macho divers. The shaved heads and stubble, combined with equipment that would make a Special Forces diver look inadequate, all add to this image. The message is that they can leap tall buildings in a single bound and endure conditions that no mere mortal could withstand. However the truth is a little different. In fact many technical divers spend as much time thinking about how to stay warm during their dives as they do planning the dive itself. The reason for this is that technical dives are more challenging than many recreational dives. They are typically deeper, longer, and colder. The intelligent technical diver recognises this and tries to protect against the cold wherever possible.
One of the main concerns of any technical diver is warmth, both from a comfort and a safety point of view. In general the deeper we go the colder it gets. A few years ago I was teaching an Advanced Trimix course in Turkey and between the surface and 80m there was a difference in temperature of 10 degrees. This meant that while we might have been comfortable on the surface you would get very cold at depth. Gloves intended to keep my hands warm at depth were uncomfortably warm during the decompression. A more common problem is that technical dives tend to be much longer than recreational dives and will usually involve long decompression stops. Even if there is no difference in temperature during the ascent it is common to get colder during the decompression. I don’t normally get too cold during the main part of the dive due to choosing the right undersuit, swimming around and the fact that my mind is occupied, but during decompression it is much more common for me to feel the cold. During long decompression stops you are not swimming around or moving to any great extent and your mind is not as occupied. It is during these long periods of mental and physical inactivity that I often feel the cold.
In addition to the comfort aspect of getting cold there are a number of very real safety issues involved. The cold can slow down your reaction speed and thought processes which, when combined with Narcosis can affect how quickly and effectively you react to problems. Cold hands can also quickly lose dexterity which can make it difficult to effectively handle equipment, operate computers, switch to decompression gas, etc.
Most importantly there is strong evidence that getting cold towards the end of a dive can increase the risk of decompression illness. During the early parts of the dive the diver is fairly warm and blood flows to all parts of the body. Nitrogen and Helium are carried by the blood flow to the whole body and the level of the inert gases dissolved in the body increases. Towards the end of the dive, during the ascent and decompression stops, the inert gas is normally carried by the blood back from all parts of the body to the lungs. However when we get cold one of the body’s reactions is to restrict blood blow to the extremities and concentrate it in the main core of the body in an effort to conserve heat. When the skin temperature starts to drop the body will reduce the circulation in your limbs, this is known as vasoconstriction. This has the effect of reducing the amount of blood flowing to the heavily inert gas-laden tissues in the extremities which in turn reduces the level at which Nitrogen and Helium off-gas from these extremities. In effect, being cold has slowed down the release of inert gas from these tissues. As a result the speed of off-gassing is slower than predicted and the excess Nitrogen and Helium in these tissues can cause decompression illness. Recent research has shown that this can cause a significant increase in the risk of decompression illness.
Due to the risk of decompression illness, suit floods and leaks are much more important to a technical diver. I know many sport divers whose suits regularly leak and for them it is merely an inconvenience however for a technical diver it can be a much more serious problem. Similarly a flooded suit can be cold, uncomfortable, inconvenient and irritating on a recreational dive but on a long decompression dive it can also be very dangerous. As the diver gets cold their decompression become less efficient. This means that at the very time they want to get out of the water they need to stay longer to make up for the inefficient decompression. Here it is a balancing act between the dangers of hypothermia and decompression sickness.
It is a combination of the comfort and the safety that makes technical divers so concerned about the particular design of undersuit they use. There are a range of undersuits that use different materials to keep the diver warm. In addition to keeping the body warm it is vital to keep your hands warm. As we have seen cold hands can cause problems with dexterity making it much more difficult to carry out certain tasks. For this reason a technical diver will also think long and hard about their choice of gloves for long cold dives. One option is to simply wear thicker gloves. The extra thickness helps provide better insulation for the fingers although the thickness of the gloves also results in reduced dexterity. The same problems apply with 3 finger mitts. These mitts have one compartment for the thumb, one for the index finger and a third compartment which contains the remaining three fingers. Having the three fingers together helps to keep them warm although the thumb and index finger get just as cold as in standard gloves. In addition having the three fingers together significantly reduced dexterity for some tasks and can make some standard hand signals difficult if not impossible. Again there is a trade off between warmth and dexterity. By getting cold we can lose dexterity but many of the gloves designed to keep our hands warm have the side effect of reducing our dexterity anyway!
Another option is dry gloves. These are gloves that are fully sealed against the drysuit and allow no water into the glove. In some designs the glove is linked directly to the airspace of the drysuit. This removes any problems with equalising the two air spaces but has the risk that a punctured glove can cause a complete suit flood. Other designs have a standard seal on the dry suit so that the dry gloves are a separate air space. In this case some mechanism is required to allow equalisation of the air space in the gloves so that the diver doesn’t get uncomfortable squeeze on their hands on the way down or excessive expansion of air in the gloves on the ascent.
The typical image of a technical diver is some macho tough guy however, as we have seen, the reality is that technical divers are more concerned about keeping warm and comfortable than most other divers because the consequences of getting cold can be far more serious on a decompression dive than on a recreational no-stop dive.
by Mark Powell
Diving an Aircraft Carrier – HMS Hermes
By: Mark Powell
There are not many diveable aircraft carriers in the world so diving any aircraft carrier is a special experience but diving HMS Hermes, the first purpose built aircraft carrier, is a unique experience. There had previously been a number of merchant ships that had been converted for use as an aircraft carrier but HMS Hermes was the first to be commissioned specifically as an aircraft carrier. The Royal Navy, despite a very traditional approach in many areas, was at the leading edge by ordering the first purpose built aircraft carrier in July 1917. She was laid down in January 1918 and launched in September 1919 and so was too late to be of any use in the First World War. She was finally commissioned in July 1923 and so didn’t see active service until the Second World War where she was based for much of her time in Ceylon, now known as Sri Lanka.
In March 1942 the Japanese Navy was ordered to carry out an aggressive raid on Sri Lanka and any British shipping in the area. Vice Admiral Nagumo, who was also responsible for the attack on Pearl Harbor, had a large fleet of aircraft carriers, battleships, cruisers and destroyers. On 9th April the Japanese launched their attack with more than 80 Japanese Zero fighter bombers attacking HMS Hermes. Due to a lack of fighter cover Hermes had to defend herself but despite opening fire with every gun it was clear that she was almost helpless against such an onslaught. Numerous bombs struck the ship and she sunk in less than an hour with the loss of the Captain, 19 officers and 288 ratings on board.
Despite being an incredibly important historical wreck HMS Hermes has lain almost unknown until recently. This was because between 1983 and 2009 Sri Lanka was ravaged by a vicious civil war which had meant that the Hermes was inaccessible to divers due to the political situation. Since the end of the civil war it has finally come possible to dive her.
The aim of this project was to determine the state and layout of the wreck. A secondary objective was to search for some of the other wrecks that were sunk at the same time as HMS Hermes. These were two support vessels, HMAS Vampire and HMS Hollyhock as well as the RFA tankers SS British Sergeant and SS Athelstane.
Despite the end of the civil war it was still a major effort to get to the wreck. Sri Lanka is a ten hour flight which is followed by a seven hour bus journey to get from the capital Colombo to Trincomalee where the boat departs. First impressions of the island are that despite being obviously very poor it is very clean and colourful with lots of small businesses. There are lots of fruit stands, hardware shops, and mechanics for the scooters and motor bikes that seem to be everywhere. I am struck by how lush and green it is. There are cows wandering the street, Buddhist shrines along the roadside, in fact all the developing world stereotypes. Later we even see three elephants wandering the road.
Diving HMS Hermes for the first time was an unforgettable experience. As we drop down the line we can see that the visibility is excellent, it drops a little after 30m but is still impressive. The shot is right on the wreck, near the flight control tower and almost on top of one of the guns. After we tie in the shot it’s time to explore the wreck. She lies on her port side in 52m/170 feet and I head along the deck towards the stern. The shot is at the forward end of the flight control tower so I can see the main part of the hull on my left and the tower on my right. As I get to the end of the tower I come across the second of the main guns. From this point onwards I am swimming along the side of the hull where the flight deck should be exposed but in this area the wreck is almost inverted so it is difficult to see the scale of the flight deck. I pass another main gun before getting to the stern. The starboard prop is standing clear and makes a very impressive sight. The portside prop is partly buried in the sand and is only partly visible. I make my way slowly back along the wreck until I get back to the shot and have a look around this area before reaching my planned bottom time of 45mins. We all have similar plans and so the whole team ascends together with smiling faces all round.
Over the next few days we further explore the wreck and document its current state. Despite obvious damage and the collapse of the flight deck there are areas that are undamaged and look almost as they would have when the wreck sank. The control tower is almost intact and gauges, complete with glass, are still present as well as a range of other fittings. Emergency lights are still in place with the light bulbs still preserved.
At the bow the anchor chains as well as the anchor are clearly visible. The decking has come away from the bow and it’s possible to see right into the fo’c’sle of the ship. A row of toilets are clearly visible together with an intact lamp fitting in the ceiling. Beyond this it is possible to see down through several decks and light penetrating through the hull shows that there is a hole in the hull a couple of decks down. Looking in through these holes gives a clear indication of the layout of the forward part of the ship. I can’t help but think of the men who served, and in many cases died, on this wreck. The wreck serves as a museum to this unique piece of history as well as a monument to the men who perished on her. I hope that anyone who dives this wreck takes the opportunity to remember these men and treats the wreck with the respect it deserves.
The wreck is home to a large variety of marine life. Large tuna, grouper and jacks flock around the wreck as well as a huge number of other fish. Some of these are of impressive size with one grouper being considerably larger than me. Some of the tuna are also a very impressive sight. As well as the fish, a huge variety of coral and other marine life means that there is significantly more life on this wreck than on the vast majority of reefs.
During the expedition and subsequent dives I have kept the HMS Hermes Association informed of all our plans. I wanted to make sure that we only ever acted in accordance with the wishes of the survivors and the families of those who perished. As I type this there is now only one survivor. Leading Seaman Stan Curtis was fascinated to see the photographs and video we brought back and was very grateful that we had paid tribute to his comrades who did not survive the attack. I also received a very humbling letter from the daughter of one of the survivors. “ I was moved to tears because my lovely Dad P.O. Henry Walker was a wonderful swimmer and loved the sea, living as we did on the coast of the Irish Sea, I long remember times spent on the beach being taught to run into the icy cold waves and dip down quickly then shown how to swim and float. He would then leave my brother and I to swim out to the Whitehaven Harbours, only to be pointed out by my Mam of a small head appearing in the distance which was that of my dad. The point I’m making is that I always thought of how cruel the sea was to take him from us, but on reading of the world class wreck – the fish and beauty of the coral, and the statement of the writer to it having More Life On This Wreck than on the majority of reefs, fills my heart with JOY and found myself thinking. What a lovely and suitable resting Place for my Father… Just what he would have wished himself. Hopefully others having lost loved ones on the Hermes 9 will be consoled by this.”
I think that expeditions like this can help to keep the memory of events such as this alive. I have also come to realise that, when carried out sensitively, they can provide comfort for those left behind.
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By Mark Powell
One of the most contentious issues amongst technical divers is the difference between the self sufficiency and team diving approaches to diving. Like a number of other issues in technical diving it seems to polarise opinions.
The self sufficiency mindset is where the diver is fully self sufficient and approaches the dive with the view that they can perform the dive on their own and would be fully able to complete the dive without a buddy. The approach is summed up by the mindset that if you can’t do the dive on your own then you should not be doing the dive at all. The other approach is team diving where strong team work and cooperation are the focus of the dive and you plan to dive with a team of divers and the team works as a well coordinated whole.
In some areas technical diving has evolved into a culture of solo diving where many experienced technical divers dive solo. All equipment choices are made on the basis that you will be diving alone or that your buddy will be of no use. Gas planning is based on the principle that it is impossible or unlikely that your buddy will be any use in an emergency and so all procedures are based on individual action. The team diving approach also has its extremists who focus on teamwork as the primary goal and consider self sufficiency to be a sign of weak teamwork.
In reality these two extreme positions are not very realistic and when taken to extreme counteract the very point of the principles. This can cause significant problems as the advocates of self sufficiency can refuse to see some of the benefits of team diving whereas the advocates of team diving refuse to see any benefit in self sufficiency.
In particular the principle of self sufficiency does not mean the same thing as rejecting team diving. For example, pioneering technical diving instructor Kevin Gurr says “Assume all dives are solo dives; do not get into the water if you feel you can’t do it without someone else to rely on.” This is a clear endorsement of the self sufficient approach and many people have taken this to be a recommendation against team diving. However Kevin then goes on to say “This does not mean you should not dive in a team, you should. Be prepared to be separated and to have to look after your self.” Similarly those who advocate team diving do not mean that you should not be able to deal with situations on your own or that you need to rely on your team.
So despite initial impressions the self sufficient and team diving approaches are not as contradictory as they might at first seem. In fact they are just two sides of the same coin.
The best technical divers obviously have to have good individual skills. Building on your own level of buoyancy control, familiarity with kit and ability to deal with difficult situations are fundamental for anyone wanting to progress in technical diving. No diver who has thought about this question for more then a millisecond would ever suggest anything less. Team sports such as football, hockey or basketball are a perfect example of the team approach but players still ensure that they work on their individual skills. Players with weak individual skills would never make it into the team in the first place. Diving with someone who is not self sufficient is not team diving. If one of the team cannot deal with an emergency situation then they are going to weaken the overall team rather than strengthen it. This means that self sufficiency is clearly a prerequisite for team diving.
The best approach then is to aim for self sufficiency within a team environment. Each diver should have enough capacity to resolve any problems they may have and have enough spare capacity to be able to offer assistance to the other members of their team. If their buddies also have enough capacity to resolve their own problems and have enough spare capacity to be able to offer assistance to the other divers then you have a very strong team.
The strongest teams usually consist of experienced individual divers with good self sufficiency and self awareness, skills they have practiced while working together in a team. Training and practice are essential in order for team diving to work successfully. Each member of the team should have similar views so they are following the same general approach. In addition good teamwork only comes with practice. You can see this with national sports teams. Each player is amongst the best player in the country yet unless they train together as a team they will not be able to perform well as an effective team.
When team diving is carried out by experienced, trained divers then it is a very safe way of diving. In the case of a problem you have more options available to help out; more gas available, more chance of spotting the problem and more ideas on how to solve it. In the case of an incident, one member of the team can be initiating a rescue while the other sends up a delayed SMB and another provides a visual reference to ensure the rest of the team can maintain depth. It is when problems occur that the benefits of diving in a team become apparent.
Of course this is very easy to say but it raises the question that if self sufficiency within a team environment is the goal how come it is not that common? The reason for this is that it’s not easy to develop these two aspects. The time and effort required to master your own skills to the point where you are truly self sufficient and then the additional time and effort required to maintain those skills is more than most people can commit to. We all have jobs, families, other hobbies and commitments which are all competing for our time. It is entirely feasible to be a recreational diver and just dive a few times a year on holiday or on a couple of dive trips. However this is not the case for technical diving. If you are involved in decompression diving, trimix or rebreathers then it is essential to ensure that you put in sufficient practice to build up and maintain your skills. Some people may take to diving more easily than others but no one is born with all the skills and knowledge they need to become a technical diver.
The development of a strong team also requires time and effort. If it is difficult to ensure that a single person can dedicate the time and effort it is even more difficult to gather a groups or team to practice together. The individual commitments of each team member and the logistics of getting them together can be difficult. However the same principle applies. If you want to become a true technical diver then it requires a certain commitment in terms of time and effort.
It is because developing strong self sufficiency skills and teamwork require such a commitment that alternative approaches have sprung up. If individual divers and their buddies do not have the individual or team skills required they take alternative approaches to try to overcome these problems. Teamwork is made more prescriptive so that it removes the emphasis on the individual diver. Alternatively, teamwork is ignored all together and divers adopt a solo diving mentality. Each of these approaches might seem easier in the short term and more appealing to those who cannot commit the time and effort to develop their individual and team skills but it is a poor solution to the problem. In the case of emergencies the lack of personal skills and self sufficiency can cause problems for you and any buddies you are loosely teamed up with. Equally the lack of team skills may cause confusion and often makes the situation worse. So even though those alternatives might seem more attractive in the short term and may be acceptable for the majority of divers where nothing goes wrong they are a poor long term solution as they can fall apart in times of emergency.
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By Mark PowellA rebreather is a fantastic tool that can be used to extend the range of what is possible in terms of exploratory diving. For deeper and longer dives, rebreathers can significantly reduce concerns over gas usage. That is, unless there is a problem. If you are unable to use the rebreather for whatever reason and need to bail out then the rebreather becomes a very expensive BCD. Not only that, but you are right back to all the limitations of open circuit gas volumes as you need enough bailout gas to get you safely back to the surface.
For dives without any mandatory decompression stops, this is relatively straightforward. As there is no decompression obligation we simply need enough gas to be able to ascend to the surface. A stage cylinder can provide plenty of air for the ascent. However, as we progress into decompression diving, the amount of gas required becomes more of an issue. The advantages of a rebreather include the fact that you can do much longer dives due to avoiding the limits of open circuit gas volumes. Together with the optimized mix that the rebreather gives you, this means that many divers will do longer dives than an equivalent open circuit diver. However, in the case of a bailout, you need to carry enough open circuit bailout to ascend and decompress safely. This means that even though you may not be planning on using those stage cylinders, you still need to carry them, just in case.
When performing any gas calculating, including calculating the amount of bailout gas you need to carry, the divers breathing rate is a key element of the calculation. Whatever your average breathing during a dive, you can guarantee that if you bailout your actual breathing rate will be much higher. There is always a reason why you have bailed out, even if it is only an imagined reason; whatever the reason, it is bound to increase your stress levels and hence your breathing rate. One of the situations where you would definitely bailout, and not return to the loop, is where you have a carbon dioxide breakthrough. In this case you would definitely not return to the loop and would need to do the entire ascent on bailout, but more importantly, you would have an even higher breathing rate. For these reasons TDI recommends using a breathing rate of at least 45 l/min (1.0 cf/min) until the first deco stop when calculating bailout gas requirements. In reality, even this rate may be exceeded for the first few minutes of a carbon dioxide breakthrough.
For deeper dives the volume of bailout gas to be carried can quickly become very significant. For dives below 80m (260 ft) this can become problematic, and the additional cylinders can introduce problems with drag and can, in themselves, become an issue due to the effort required to swim with them. TDI believes that each diver should carry enough bailout gas to be able to get them to the surface. An alternative approach is team bailout where the divers between them carry enough bailout gas to get one team member to the surface. This is not a technique to be used without specific training and unless you are diving within a well-practiced team. For most rebreather dives this means that the limiting factor for the dive is not scrubber duration, exposure to CNS or anything else related to the rebreather itself but rather the amount of bailout that can be carried.
The gas selected for the bailout cylinders requires some thought. As they will hopefully not be required, rebreather divers tend to use a standard set of bailout cylinders and gasses that will be used for repeated dives. The first bailout bottle needs to be breathable at the maximum depth as the diver may well have to bailout on the bottom. It is common to use a first bailout that has a higher partial pressure of oxygen than the setpoint being used on the rebreather. This is to optimize the decompression ascent. Subsequent bailout gases are chosen by balancing out the decompression requirements and the gas planning requirements.
Another technique that is sometimes used, and is starting to appear in some planning tools, is to modify the decompression model so that a different approach is used for a bailout ascent rather than a normal ascent. When ascending normally the diver may well want to use deep stops or some form of bubble model approach. However, during a bailout the diver may want to get shallower slightly faster than they would otherwise have liked in order to reduce gas management problems.
Until rebreathers with built-in redundancy of all features or bailout rebreathers become common place, we will still need to plan for bailout. Until that point, rebreather divers will still ultimately be limited by the restrictions of open circuit gas calculations and the ability to carry sufficient bailout.
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