Couple of things:
Unfortunately I feel that divers in general are poorly informed about the choices available to them and their relative benefits and costs. In my opinion this is because the dive industry (manufacturers, dive shops, training agencies, dive magazines, etc) is strongly focused on product sales and promotion rather than encouraging a critical assessment of the products, techniques and services available. How often do you see a bad review of a peice of equipment? Advice may be sought from dive shop staff on equipment when they themselves may have limited knowledge of the choices available, beyond the products they are encouraged to offer by distributors or the standards of one training agency. I feel this has a lot to do with the approach taken to diver training (even through to Instructor level and beyond) where participants are not encouraged to take the time to develop there depth of knowledge and experience before progressing to further training. Product development is driven, IMO, more by dubious whims of marketting rather than genuine need, promoting gimics that offer solutions to problems that don't really exist or encourage convoluted solutions at the expense of good technique, dive planning and skill development. Bandaid solutions appear without a systematic evaluation of the root cause of a problem (without examining training, skill review, diver attitude and fitness or other elements of the divers kit). The accumulation of bandaid solutions is demonstrated in the range of "accessories" the average open water diver carries and the unnecessary level of complexity in basic dive gear. In combination I believe these factors have allowed many ill conceived designs and ideas to entered the market and often become entrenched as some sort of industry standard. It's my assertion that these ill conceived choices compromise enjoyment and often safety and encourage poor technique. ...The focus of this site is
primarily equipment but it is vitally The recreational diving environment is very forgiving in general but this should not be an excuse for complacency (particularly if standards continue to be compromised and these compromises become the new standards). I work part time in the dive industry and on virtually every dive I am confronted by divers unable to maintain proper buoyancy control and trim (floating to the surface without the support of a mooring line or kicking up the bottom due to poor trim or finning technique) or struggling with their equipment for one reason or another. Divers remain dependent on their equipment and skill for survival (even at the bottom of a 2 metre pool, the fact remains you can't breath water). Also, divers often pursue more challenging dive experiences as there confidence grows. It is in these environments that poor technique and equipment choices, inadequate fitness and mental focus and a limited focus on the fundamentals of good diving during training (buoyancy control, proper weighting, trim, finning technique, buddy skills, dive planning, etc) can prove critical. Scientific divers will also appreciate the value of reliable equipment when the cost and time constraints associated with field studies are considered (you can't afford to miss opportunities due to preventable equipment failures). The focus of this site is primarily equipment but it is vitally important divers don't loose sight of the bigger picture. ...By freeing divers from the constraints imposed by poor technique or equipment DIR allows greater enjoyment of the diving experience and the opportunity to achieve far more during a dive and have a far greater margin of safety. There is also the opportunity to significantly reduce the impact divers have on their environment. Equipment is a small (but important) part of DIR, facilitating other aspects of the system. DIR encourages a critical assessment of equipment choice with a focus on the underlying functionality of a peice of equipment and its place within the system. DIR encourages a holistic approach to diving encompassing training, skills review and assessment and even diet and fitness issues. This systematic approach to diving is unique to DIR. By freeing divers from the constraints imposed by poor technique or equipment DIR allows greater enjoyment of the diving experience and the opportunity to achieve far more during a dive and have a far greater margin of safety and comfort. There is also the opportunity to significantly reduce the impact divers have on their environment. ...be an informed consumer. Unfortunately you don't hear a lot about DIR in the dive industry. I have found it difficult to find information and access equipment that I consider optimal in Australia. The purpose of this web site is to help my own learning process by getting feedback from divers around the world, as well as hopefully helping others who wish to access equipment, training and resources. Anything that makes diving safer and more enjoyable is beneficial at all levels of diving. I believe divers should take responsibility for their own learning and be as informed as possible about the choices available to them - be an informed consumer. There is also an economic benefit in getting the right gear first up. I know. I have spent a lot on gear over the years and made plenty of dubious choices (check out my body position in these images compared to the couple at the end of this section, its taken me 12-13 years to overcome the bad habits I learnt when I started diving (if only GUE were around back then))...
Tim Hochgrebe of Planula productions kindly prepared a short MPEG movie of me swimming through "Split Bommie" at Julian Rocks Marine Reserve, northern New South Wales. The video shows how streamlined and neat the whole setup is underwater (actually even better now, this video was taken before I changed over to a dual outlet valve and 7 foot primary). Other images on this page show what my gear looks like on. They highlight the low profile of the setup compared to conventional jacket style BCD's as well as the efficient/structured layout. Everything is where you need it, when you need it (don't have to go searching). Facilitating a rapid respond to any problem. Keeping everything close to your body (including hoses, all custom length) helps prevent entanglement and, in combination with the tape harness and wing, provides a clean, low drag setup. Rather like not wearing a BC at all (I find it quite easy to fin and glide in the setup, reducing the effort required to get around (particularly in current)). Thanks to Eric Passfield for the following pictures (both shots were taken recently while I was helping out with Erics coral bleaching study in Byron Bay, for more details see my SCUBA scenes site).
This section gets down to the nitty gritty of how I put together my setup and some of the guiding principles I've used. I get a lot of questions about my equipment so hopefully the discussion included below will go some way to answering some of these. Remember though, I'm only learning about this stuff myself. Don't take my opinions as gospel, seek information from a range of sources and use your own common sense - or save yourself the angst, contact GUE and do a course! I have included links in each section to web resources I found handy. General principles | Fins | Mask | Harness | Wing | Regulator/hose layout Attachments | Weighting and thermal protection
General principlesEvery dive professional and dive shop will have an opinion as to which brand or style of equipment is best and how that equipment is best used. Often I believe this is more influenced by the relationship between shops/dive professionals and equipment suppliers than anything else. To be fair though I think its also reasonable to believe that staff in dive shops are often exposed to a limited range of product choices (or perhaps too many, given that most products repackage the same technology and there is a plethora of brands and models). Its equally difficult to blame equipment manufacturers for promoting their products and developing their business through every means available. Its surprising though that in an equipment intensive sport very little critical assessment is made of products, even by apparently experienced divers (who often make, in my opinion, very poor equipment choices). Three areas in particular that I believe are given far too little regard are the issues of drag, entanglement risk and reliability. Even a small increase in surface area creates a significant increase in energy consumption... Drag... In most active sports participants strive to minimise drag. Cyclists wear specially shaped helmets, slick suits and adopt low drag body postures to cut through the air quickly. Water is far denser than air. Swimmers wear super slick swim suits and shave their heads. Most divers on the other hand wear bulky jacket style BCs with baggy pockets (full of accessories), hang all sorts of things off themselves and adopt swimming postures which increase swimming resistance. Resistance increases as the cube of velocity. Moving through a dense medium like water, doubling your surface area requires nearly 16 times the energy to move at a given speed. Even a small increase in surface area creates a significant increase in energy consumption (and therefore air consumption and physical stress). The faster you try to move through the water the harder it gets. If you dont believe me consider how easy it is to move through the water with just a mask, snorkel and fins compared to a bulky SCUBA unit. Or perhaps consider how much fuel a large van uses travelling on the open road compared to an aerodynamic car of similar engine capacity. Moving around slowly the difference in drag (or air consumption) is not always apparent but try to get a move on or swim against a current and drag becomes a big issue. I know from experience that I notice the difference in drag between a thin wetsuit and drysuit (a bulky jacket style BC feels like I'm dragging another person behind me compared to my harness and wing). Why make things harder than they need to be? It's better (safer) to have plenty in reserve rather than wasting energy on drag inducing BC designs or poor trim. What happens when you need to tow another diver or swim back to a line against a current? The more you have in reserve the better. Choose a streamlined, low drag harness and wing and learn how to maintain a horizontal swimming posture. Entanglement... Entanglement is another issue I consider important when examining the pros and cons of a piece of gear. When I learnt to dive I was told to thread my fin straps to the inside and tape them up so they didnt snag lines (youll find similar advice in the NAUI Advanced SCUBA Diver Manual and a number of other sport diving guides). I was told to wear my knife on the inside of my leg for the same reason and clip all my gauges and regulators up out of the way so they didnt dangle and catch on the bottom. It seems manufacturers of dive gear have forgotten these lessons, promoting products with a host of entanglement points and an unnecessary level of complexity. ...if a piece of equipment has features which add nothing to its functionality (or worse compromise the functionality for the primary purpose for which it was designed), then that piece of equipment should be avoided... Reliability... In general the open water diving environment is very forgiving. However, small problems can often conspire to create much larger problems and problems usually present themselves at the worst possible time (eg. quick release clips on fins breaking or failing to close on rough surf entries off rocks). I strongly believe that if a piece of equipment has features which add nothing to its functionality (or worse compromise the functionality for the primary purpose for which it was designed), then that piece of equipment should be avoided (or perhaps modified). I also believe that many innovations in the dive industry are primarily aimed at product placement rather than genuinely improving a product. There are very few genuinely new technologies, most "innovations" merely repackage the same technology. When this compromises the primary function of a product or promotes poor technique then again these products should be avoided. Further, some products sold in dive shops are entirely unsuitable for the rigors of the underwater environment. I have found many products over the years that through poor design, unnecessary complexity or just cheap construction, don't last more than one or two dives without failing. There is just no excuse for this in a sport where the proper functioning of a peice of kit can be a matter of life and death. Equipment used in extreme environments needs to be of simple solid design. I have no qualms pointing out poor design features or poor products when I see them (not always a popular approach, but one I'd encourage). ...not one single manufacturer produces the "best" gear. My view is that not one single manufacturer produces the "best" gear. Rather different manufacturers produce pieces of equipment that are optimal in that they employ simple functional design and do not compromise this functionality with a lot of gimics or unnecessary "features" (also putting the cost up). Maybe its because my diving career overlaps a period of development in the diving industry (when many people still made or heavily modified items of equipment) that I dont see a problem with making minor changes to gear (or building some less critical items from scratch) if no one product is just right. "You really have to bust your ass to stay ahead of the dive industry's 24-7 effort to f**k up everything they can." - George Irvine, Director, WKPP. Some items needed for a basic single tank DIR setup are hard to get hold off in Australia, and becoming harder to find. I had to go to a bit of trouble to track down distributors so I have listed distributors for some items to help others in the same boat. Unless another retailer is shown most gear was ordered through my local dive shop, Byron Bay Dive Centre. It pays to make sure the distributor knows exactly what you want (if you have a good relationship with your dive shop it may be best to fax or ring through your own orders or confirm the details).
MaskA mask is often the first piece of equipment a new diver will buy. Masks provide a window into the underwater world. A good, reliable mask is essential to maximise safety and enjoyment. As with most pieces of equipment a good mask may end up costing a bit more but the extra investment pays off in the long run. By far the most important criteria for choosing a mask is fit. Silicone
skirts are preferable to rubber and silitex (often found on cheaper
masks). Silicone generally fits the face and seals better than cheaper
materials. Placing the mask on the face and looking up toward the sky
the mask skirt should make contact with your face all around. A slight
inhalation through the nose should hold the mask to your face without
putting the strap on. For diving and snorkelling a low volume mask is preferable. Lower volume means less effort to clear and less drag. Complicated designs (multiple lenses, purge valves, and so on) should be avoided as they have more potential for failure. More lenses equals more potential leaks. Fancy purge valves offer no advantage to a skilled diver and simply introduce unnecessary failure points (high potential to leak, particularly in silty environments). Simple attachments for mask straps are preferable to complicated attachments. On my Technisub mask I have removed the swivel attachment (which catches line or the bungie for my backup reg) and simply thread the velcro strap through the hole left behind. I quite like the look of frameless masks like those produced by Scubapro, Mirage and Oceanic. Frameless masks are low volume and provide excellent field of view, good as spare masks too as they fold up guite flat. Quite happy with my Technisub Look too. The fit is better than any mask I've owned before. I also prefer black silicone skirts to clear. In my opinion glare from the sides reduces visual range and contrast in most lighting conditions (just an opinion). Divers easily adapt to a small loss of peripheral vision. After market neoprene straps are a good addition to a mask... After market neoprene straps are a good addition to a mask. These are unlikely to break and offer a comfortable secure fit. Once set to the correct size, neoprene straps never need adjustment. I put the velcro to the inside to avoid entanglement and prevent the strap accidentally being loosened. The mask strap is on the outside of the hood to prevent heat loss and allow for easy, one handed adjustment.
FinsFins are an important piece of equipment for divers. Without fins its extremely difficult to get around underwater. Without fins the diver is often at the mercy of the elements (ever tried swimming in full SCUBA gear without fins?). There are a range of fin designs around at the moment, all touted to be the most efficient or the easiest to fin. Personally I dont have much interest in all the rhetoric about different blade designs. Generally I feel most fin designs are poorly conceived and ignore the fact that fins are used to perform a range of tasks other than propelling the diver as fast as possible in one direction (fins are used for stopping, maintaining position, turning on the spot, reversing, a whole lot of things). What interests me most though is how effectively the fin is secured to my feet. I want to be able to get the fins on and off my feet with a minimal amount of fuss and have the things stay on my feet for the whole dive without any adjustment or messing around. I also want to minimise the chance of my straps catching lines or other entanglements. Oceanic stainless steel spring straps are the only type of fin straps that fit the bill...
Whats wrong with the so called quick release straps sold with most fins now-a-days? Where do I start. First let me tell you that apparently sales of fin straps outstrip the sales of fins by ten to one (ten times as many sets of straps sold as fins). Why? Rubber fin straps break. The plastic components of quick release straps break. Breakage can also result in the loss of a fin. Stainless springs dont break. Second thing to consider. Quick release straps arent, they are just another thing to mess with before, after and during (when they come loose) a dive. I can don and doff my fins faster than someone with quick release straps. I never adjust or mess with my stainless straps (there are simply NO adjustment to make simple). Third thing to consider. The ocean is full of sand. Particularly on beach entries sand can enter the mechanism of quick release straps and prevent them closing or opening. I have seen folks get into heaps of trouble in the surf zone (where you cant afford to muck around) because their clips have jammed and wont close. Fourth thing to consider. I have seen a number of folks loose their fins because plastic straps (with flimsy attachments) have failed during dives (on at least one occasion this resulted in an uncontrolled ascent to the surface admittedly poor techniques played a part too). Final thing to consider. Quick release straps are a major entanglement risk. The design makes this unavoidable. Like many "innovations" in the dive industry "quick release" straps are a solution looking for a problem. They create more problems than they solve (actually I'm not even sure what problem they're actually trying to solve?). Fin goes on (FIN_ON.MOV) | Fin comes off (FIN_OFF.MOV
HarnessA tape harness is simple, cheap and reliable and can be used for just about any type of diving (no need to change your harness when you change your diving activity (tech, cave, scientific, etc)). It provides a low profile, comfortable and secure fit. This type of harness does not shift position underwater like a conventional jacket style BC. Nor does it ride up around your neck on the surface or loosen off during a dive like jacket style BC's with "quick release" shoulder straps. Unfortunately divers have a distorted image of what a BC should look like (jacket style BC's are more a fashion accessory or status symbol than a truely functional peice of kit). New divers are taught that they "need" a whole lot of "features" which in truth just complicate the setup, promote poor technique and introduce a whole host of new failure points. A good peice of kit performs the basic function it is designed for and doesn't complicate its functionality by pandering to whims of marketting. A BC harness is not a backpacking harness, you don't need a whole lot of padding and adjustments. Once the shoulder loops, waist strap and crotch strap are set right you can forget about it. The harness slips on and off effortlessly without any need for quick release clips and never needs adjusting. The harness I made myself from a continuous length of weight belt webbing (there is an excellent diagram showing the layout of a DIR harness at http://www.gue.com/equipment/backplate6.html). For more images of a DIR harness threaded correctly see... --> http://www.wkpp.org/equip_moreimages.htm I don't use a front or rear D-ring on my harness any more. The front D-ring isn't really necessary since I don't own/use a scooter. I used to use a rear D-ring but was concerned that storing items here might be an entanglement risk if I needed to dump a weight belt in an emergency. For the same reason I don't have tank boots on my tanks, I've had belts get hung up between the boot and my waist during rescue training drills so they pose a real danger. Some people feel they need quick release clips on a BC or harness. These are totally unecessary and introduce additional failure points and more complexity and potential entanglements to your setup. They can loosen off during a dive making the tank move around on your back underwater or on the surface the BC can float up around your neck. They also interfere with the correct placement of backup lights and the bungie used to contain the inflator hose (catching or dragging on the bottom and giving at least one manufacturer a dubious excuse to remove the inflator hose altogether (again the wrong solution caused by the wrong equipment choice in the first place)). I feel a lot of the reason people feel they need these is that BC's with these sort of straps also have quite small shoulder loops making it necessary to unclip or loosen the straps to get out of them. As you can see from the above images a propel fitting harness provides ample room to extract your arms from the loops without any need for quick releases. The following video clips show how easily the harness can be removed above or below the surface using the "flip over" method. Once the waist strap is undone the harness comes off very easily using this or other methods. Divers can also be extracted from the harness easily during a rescue by pushing the arms back through the shoulder loops. Another option is to simply cut the webbing with a knife or shears. Importantly though the harness can only come off when it is intentionally taken off (there's nothing to work loose or fail). At all other times it provides a secure and comfortable fit, the tank can't move around underwater on the divers back as is often the case with sloppy fitting jacket style BC's. The crotch strap is an essential part of a diving harness (this was historically recognised but seems to have been forgotten by manufacturers of "modern" SCUBA equipment). Many of the problems with trim and comfort associated with BCD's currently promoted by the dive industry eminate from the fact that these products don't have a crotch strap. Unlike a backpacking harness a divers harness must secure the divers kit in three dimensions. The crotch strap is essential to prevent the BCD floating up around the divers head and shoulders underwater or on the surface. In combination with a simple tape harness the crotch strap prevents the divers kit moving around underwater. It also keeps the waist strap from riding up against the diaphragm and ensures some of the buoyancy in the wing is kept lower down on the divers body (improving trim). The crotch strap is not uncomfortable. I don't even notice it.
A metal backplate allows a seemless transition from single tank to
double tank diving if desired but one of the biggest advantages IMO
is in neatly redistributing some of the weight from around the hips
(without the drag caused by special weight pockets or weight integrated
BC's (a bad idea anyway IMO, everyone knows how to use a weight belt
and should be able to ditch one in an emergency, all weight integration
systems are different and some don't even look like weight systems (some
suggest familiarising yourself with a buddies gear should be part of
the pre dive checks but what if it isn't your buddy performing the rescue?)).
Bringing weight up further on the body promotes horizontal trim and
the associate benefits (less energy required to swim, less damage to
the bottom, less silting, etc) and puts less strain on the lower back. Pictured opposite is a home made sheath and knife to accompany the harness. The knife cost around $3.50 (AUS) to make. Most important thing is that the blade passes right through the handle, a cheap steak knife is fine. I ground the blade down to remove the point and form a chissel end that could be used as a screw driver at a pinch. The sheath was probably a couple of dollars at most. I made mine from left over peices of webbing, folded to form a pouch for the knife and loop for the waist strap to pass through (glued and stitched along each side). All the stainless steel D-rings and bolt snaps for my harness were bought from a local chandlery (boating supply store). Wings and back plates (or even full kits including the tape harness if your not a do-it-yourself-er) are available from Halcyon. Actually in my experience (having bought all the bits and built up my harness from scratch) it's cheaper in the long term to just buy a complete Halcyon package from one of the regional retailers like Paul from Inner Realm in New Zealand or Trickey at Dive Centre Manly. Saves a lot of time and unnecessary expense in the long run. Take care when your trying to save a few bucks... Take care when your trying to save a few bucks. I bought some back plates a while back that were entirely unsuitable for my needs (they don't work with the newer design Halcyon wings and in my view they are too wide to fit properly - although some people apparently like them). I think the standard plate design produced by a number of companies (Halcyon, OMS, Dive Rite, etc) is a much safer bet. Also, make sure that the plate has slots for threading the tank bands through and that they are the right width apart (I cut the slots myself - buy the Halcyon plate, it's easier). --> Standard and non-standard plate designs
Wing I use a Halcyon Pioneer 27
pound single tank wing. I have yet to find an acceptable alternative
made by any other manufacturer. Both Scubapro and Dive Rite produce
travel wings with minimal lift but unfortunately neither of these wings
are made to fi ...most divers over estimate the amount of lift they require in a BC. I'm of the view that most divers over estimate the amount of lift they require in a BC. By considering the buoyancy characteristics of all your gear (tank/s, exposure suit, lights, etc) and determining the change in buoyancy experienced during a dive, it is possible to determine the minimum lift required. Some equipment will be negatively buoyant some equipment will be positive, and this should be considered before adding additional weight. During a dive only the buoyancy characteristics of tanks and wetsuits change (and perhaps drysuits if you add excess air for warmth, generally dry suits should be worn "shrink wrapped" and a little air added only after 6-8 metres when squeeze is more significant). An alumium tank will be slightly negative at the start of a dive and slightly positive at the end (steel tanks are generally undesirable IMO for single tank diving, because often they are so heavy no weight is carried in a ditchable form, making the diver overly reliant on lift from the wing to make an ascent). A wetsuit is positively buoyant but compresses and becomes less buoyant with depth (and age/use). I now tend to use several thin, close fitting layers of neoprene (focusing on the areas that loose most heat, head and torso, upper arms and legs) rather than single thick layers. It is hard to quantify how successful this approach is, but I feel it works. Once your aware of the change in buoyancy in your tanks and suit it is possible to work out how much extra weight is require to remain neutrally buoyant near the surface at the end of a dive with no air in your wing (when your suit and tank are most buoyant (a consideration for drysuits might be how much extra air is added to be comfortably warm on deco)). If your neutrally buoyant at the end of the dive (the buoyancy of your suit and tank is balanced by the weight of your backplate, canister light (if you have one), weight belt and any other gear) then it stands to reason you will be negative at the start of the dive at depth (when the tank is heavy and your suit is compressed). Knowing how negative will tell you roughly how much lift is required in a wing (plus a small margin for error, to allow for a more buoyant exposure suit or perhaps to float your gear independently on the surface). Remember, you should never use your wing/BC as a lift bag. Allowing extra lift to retrieve weight belts or anchors or other finds is encouraging poor technique (get training and use a lift bag or just leave it behind). Note, in my view it is import that you can ditch enough weight to ascend and remain on the surface without assistance (in the event of a BC failure). This means that some weight should generally always be retained in a ditchable form (weight belt or canister light). Though clearly ditching the bulk of a divers weight would make it virtually impossible to control the ascent (one of the reasons I don't think all of a divers weight should be on a weight belt). .
Regulators/hose layoutThe following shows my prefered hose layout for a single first stage and current layout for a dual outlet (H) valve. A similar dual outlet configuration, for a Beuchat Y valve, is shown on the H2O Adventure gear website.
There is some debate over the use of dual outlet (H and Y) valves. I'm undecided but certainly agree that dual outlet valves do not circumvent the need for twin tanks and an isolation manifold in overhead environments (including deco diving). Nor do they circumvent proper buddy or team diving skills. However, I do feel using a dual outlet valve makes hose routing a lot cleaner compared to a single first stage (see below). There is also redundancy between wing and dry suit inflators and primary and backup regulators. Meaning in the event of a first stage, hose or o-ring failure, air supply and buoyancy control can be maintained. With a single first stage it may be preferable to use a longer hose for the backup and route it under the arm (although I'm not keen on this option, not as quick to deploy).
Breathing and donating the long hose... ...has always seemed the most obvious and logical response to an OOA scenario to me. Breathing and donating the long hose is something I was taught by my OW Instructor (NAUI) and this has always seemed the most obvious and logical response to an OOA scenario to me. The diver in most immediate need quickly receives a known working regulator. I can donate my primary reg and retrieve my backup almost instantly (no delay while you go through some sort of elaborate dance to find an "occy" and unclip or remove it from a pocket). By donating the reg in your mouth the OOA diver immediately receives a known working regulator. Because the backup regulator under my chin is MY regulator in the event I need to donate my primary, I check it works properly on every dive (How often are occy's checked? What guarantee they won't fall out of a retainer and drag in the sand or get hooked up somewhere hard to reach (I've tried just about every type of retainer on the market, non are fool proof)?). See... --> Modifed S-Drill | Donating to a buddy --> For more skills videos see http://www.rec-scuba.com/gallery/DIR
or http://www.fifthd.com/
The backup regulator needs tobe easy to access and secured in place to ensure it is always available when needed. The best method of attachement in my view is using a bungie cord necklace held in place by the cable tie that holds the mouth peice on. Modified S-drills should be performed at the start of every dive to ensure the backup regulator is in place and the primary can be fully deployed. While a 38 or 40 inch can be used for the primary regulator (I dived with one for 6-8 years) there is no way I would go back to one now. The shorter hose usually ends up sticking way out the side and gets entangled on things (some use shorter hoses with elbows so they can be routed under the arm but these introduce an additional failure point). The longer hose (5 or ideally 7 foot) on the primary is brilliant IMO, offering lots of room to swim beside an OOA diver away from trouble or control a panicked diver. Everyone who has seen me in action with a long hose appreciates the benefits. The longer hose can also be more neatly routed without the need for elbow joints or other modifications or the use of non standard regulator placement (like routing one of the regulator hoses over the left shoulder - breathing supply should always come over the right shoulder (this is just common sense, you or your buddy always know where to find a regulator that way no matter how bad the vis is)). Excess hose length introduces clutter and potential entanglements... Correct hose routing is important. Correct hose placement facilitates a rapid respond to a problem. Keeping everything close to your body helps prevent entanglement and, in combination with the tape harness and wing, provides a clean, low drag setup. Excess hose length introduces clutter and potential entanglements so I buy custom length hoses. I currently use a 7 foot (80inch) primary hose, 24 inch backup regulator hose and 24 inch SPG hose (my wing inflator came from Halcyon (it's either 22 or 24 inch) and the dry suit inflator (if used) is 28 inch). The next few images are front on views of my gear (note that you can't even see the wing in some pictures). I changed over to a longer (7 foot) primary hose recently but I have left some older images showing my hose layout with a 5 foot hose for those who prefer this length (personally I wouldn't bother). Routing under a canister light is preferable but I find tucking the hose under the knife works fine if I don't have the light.
...I don't use hose covers or boots on gauges. These can hide damage to hoses or loose fittings. Left and right side views. The backplate is not correctly adjusted in these images. For a discussion of how to correctly size a harness and backplate see... http://www.baue.org/faq/backplate_sizing_inline_images.html Notice also that I don't use hose covers or boots on gauges. These can hide damage to hoses or loose fittings. On at least one occasion I have seen an SPG gauge and console blow off a hose during a dive because it had worked loose over time and the boot had masked the problem. Obviously hose protectors are needed on the first stage end of hoses to prevent damage, but these should be moved and hoses checked regularly.
My webbing is a little short, normally the buckle on the waist strap would come round further, closer to the backplate on the right side (to hold the canister light in place). Unfortunately since breaking my wrist (and having a plate inserted) I don't have the flexibility or strength to do up a buckle this far back and have to settle for holding my canister light in place with a second buckle (sub-optimal but this does allow me to don and doff gear in open water without loosing the canister).
AttachmentsI use stainless steel bolt snaps (bought from a local chandlery) ONLY for attaching hoses or accessories. These are the only reliable option. So called "suicide clips" or gate clips are an accident waiting to happen and have no place in diving. Likewise these fancy plastic clips with quick release buckles or retracting cords. Plastic clips will break at the worst time and anything that looks complicated or relies on some sort of mechanism to retract cord will inevitably jam up. The ocean is not the place for unnecessarily complicated solutions. Keep it simple and reliable. The ocean is not the place for unnecessarily complicated solutions... Even using high quality stainless steel bolt snaps it is possible to have a clip lock shut. It is important any gear can be pulled or cut loose if necessary. Never have metal on metal attachments. My primary regulator and pressure gauge are attached using a breakaway tank O-ring (the idea is that a hard tug should break the O-ring). Nylon line (cave line) is used for my strobe, torch and other accessories which shouldn't need to break away (but can be cut loose if necessary). I have also used a loop of bungie cord (tied with a double fishermans knot or a square knot) to attach some heavy items or other items on the fly, like spare weights and tape measures.
*I don't think this method of attachment is recommended any more (if it ever was). Both the pressure gauge and the primary regulator bolt snaps could be attached using cave line. For detailed instructions on how to attach a bolt snap using cave line or an O-ring see... http://www.mindspring.com/~toddleonard/caverig/howknot.html
TanksThe tank of choice for DIR single tank diving (and for use as a stage in technical or cave diving) is the Luxfer Aluminium 80 (SO80 - US or SA80 - Australia). This tank has the most favourable buoyancy characteristics, shifting from slightly negative when full to slightly positive when empty. Some of the reasons this tank is prefered include:
The choice of valve and valve knob is also important. Generally speaking a DIN valve is the prefered choice. DIN valves trap the O-ring more effectively and are less susceptible to failure or damage due to impact. Straight valves are prefered to angled valves as these confound hose routing and expose the first stage more to impacts. All valves should have the standard clockwise OFF and anti-clockwise ON spindles. Plastic and metal valve knobs should be avoided, they are prone to breaking (plastic) or bending (metal) making it impossible to close or open a valve. I also find these kind of knobs much harder to turn (particularly during valve drills). The ideal valve knob is the Sherwood rubber knob with steel inserts. These knobs are large enough and positive enough to turn easily and cannot shatter or distort if you collide with the roof of an overhang or wreck.
Divers should be able to reach their valves easily while wearing the SCUBA unit and practice valve drills regularly. Although popular practice in the dive industry it is best NOT to turn knobs half a turn off. This can easily lead to confusion when dealing with a failure and may also result in a false out of air. I have had to deal with a number of false OOA's when divers turn the knob the wrong way (often because a dive master has already turned a tank on for them) and then leave the valve slightly on. Upon reaching depth breathing becomes difficult or impossible and the diver believes they are out of gas. If a valve is turned either fully on or fully off there can be no chance of this happening. There is also no confusion or wasted time should a diver need to turn off a valve when an O-ring or hose failure occurs. The right valve and knob combination, properly cared for, will not jam. Sherwood knobs are very easy to turn.
Weighting and thermal protectionI've owned a number of wetsuits. At least four two piece 5mm suits, a couple of semi-dries and a number of surfing and warm water suits along with a range of accessories. Wetsuits are the main stay of the diving industry but now I own one I love my drysuit. I wouldn't go back to a two peice 5mm suit now (though I do still use a semi dry a fair bit - particularly for research diving where the suit is getting rough treatment). As I don't currently use a lot of weight diving wet or dry though I use an aluminum backplate (rather than the more popular and heavier stainless steel) so that I can retain a good proportion of my weight in a ditchable form (weight belt or light canister). Note that I used to retain some weight in a tank keel weight. I now agree that this approach may pose an entanglement risk or a risk of overweighting on the surface (in the event of BC failure at the start of a dive), which outweighs any potetntial benefit for airway mitigation or trim, I don't recommend using a tank weight. At present (diving in shorties or thin summer suits) I rarely need any weight but if I did it would make sense to put this weight on a weight belt. This allows weight to be ditched in the event of a BC failure on the surface. When I eventually get thicker thermals I may use a stainless backplate with my drysuit to move excess weight off my belt and maintain a "balanced rig". ...I adjust myself for neutral buoyancy at 6 metres with no air in my wing and around 35 bar in my tank. I try to consider the buoyancy of all items I carry and I adjust myself for neutral buoyancy at 6 metres with no air in my wing and around 50 bar in my tank. With a metal backplate (aluminium or stainless steel) you get excellent balance in the water, you swim horizontally rather than feet down/head up like a conventional SCUBA setup (where all the weight is in a belt around your waist and all the buoyancy in the BC (usually up round your chest)). Horizontal trim is very important in minimising fin damage and silting and for improving efficiency (a horizontal diver presents less surface area for drag and will move through the water much easier). For a good description of stability issues in configuring your equipment see... http://www.baue.org/faq/dynamic_instability.html I generally use one of the following suit/weight combinations (in sea water):
Most new divers use more weight than they require in my opinion. In addition to this weight is often poorly distributed over the diver body. Distributing weight throughout a divers gear can significantly improve trim and comfort in the water. Two important things to remember though. Firstly, open water divers should strive to be neutrally buoyant with low tank pressure, no air in the wing/BC and be able to float comfortably during a safety stop (without struggling to stay down). Secondly, for safety, divers should retain sufficient weight in a ditchable form to allow them to overcome neutral buoyancy at the start of a dive (when they are the heaviest with full tank and compressed wetsuit (if used) at depth) in the event of a wing/BC failure, ascend to the surface and float comfortably on the surface. Not quite so critical with drysuits as these provide redundant buoancy and both the wing and suit failing on a dive is unlikely (particularly if they are supplied from different first stages). Many experienced divers demonstrate poor form by using heavy steel tanks and carrying no ditchable weight. While this kind of setup may be suitable for cave divers where an overhead prevents a direct ascent to the surface anyway and a redundant air supply is available, this kind of setup is down right dangerous in an open water setting (at least in recreational diving). A more sensible approach is to reliably evaluate your weight requirements and ensure that while some weight is distributed through the setup (in the form of a metal backplate) some remains in a ditchable form (canister light and/or weight belt). ...a backplate, wing and harness system offers considerable advantages over conventional jacket style BCs or tech style wings. Metal backplates, while commonly used by technical divers, are not often seen by recreational divers. This is unfortunate as a backplate, wing and harness system offers considerable advantages over conventional jacket style BCs or tech style wings. When discussing weight systems the most important advantage is that some weight is incorporated in the backplate. This allows weight to be removed from the weight belt and effectively redistributes weight, improving trim. Not only that but a metal back plate redistributes weight without any significant cost in terms of drag. Some commercial BCD systems have integrated weight pockets on the back, front or sides. These not only add complexity to the whole set up but also increase the profile for drag. Backplates can be bought in a range of weight configurations (though 3 pound aluminium and 6 pound stainless plates are most common) and additional weigh added if needed in the channel of the plate (again without creating additional drag). The choice of weight depends on the exposure suit used and the requirements of the individual. I tend to use very little weight so I use an aluminium backplate so I can retain some weight in a ditchable form. All divers are trained how to ditch a weight belt during training... ...it may well be that a divers buddy is not the one called upon to perform a rescue. I have mentioned that integrated weight systems add drag to a setup. I also believe that most are ill conceived. All divers are trained how to ditch a weight belt during training. Therefore everyone should know how to ditch a weight belt. Most integrated systems on the market use different release mechanisms (some are barely recognisable as weight systems). While familiarising ones self with a buddies gear prior to a dive is essential it may well be that a divers buddy is not the one called upon to perform a rescue. For these reasons (and the fact I hate lifting integrated BCDs onto dive boats) I do not recommend the use of integrated weight systems. Weight belts are also considerably cheaper and easier to replace. Divers should also be aware of the weight characteristics of other items of gear used. A canister light for example can be up to three pounds or more negatively buoyant and can allow further weight to be removed from the weight belt (in fresh water a canister light is all the weight I need with a drysuit and aluminium backplate and tank). Canister lights can also be considered part of your ditchable weight if properly configured (on the waist belt of a harness).
I have had good service out of the Sonar, Seasuit and Billabong wetsuits I've owned (no complaints with my Mares semi dry though). My last Seasuit wetsuit was fitted with a pocket by the manufacturer (although on the first attempt the pocket was put in the wrong place). It's worth putting in the extra effort to get things the way you want them. DUI pockets can be retro fitted to wetsuits or drysuits if need be (choose pockets with velcro closures ONLY, zippers can jam). The correct DIR pocket layout is standard velcro pocket (CLF200) on the right hip and bellows velcro pocket on the left.
I try to avoid carrying too much. If your going to go to the trouble of setting up a nice low drag, uncluttered setup, why mess it up by carrying a whole lot of "stuff". Often the rationale for carrying many of the accessories people are tempted to attach to themselves doesn't stand up to close examination (proper dive planning, buddy skills and other fundamental diving skills make them redundant). The items I consider essential include; a knife (sometimes also carry scissors in my pocket as these are easier to use on marine critters that are snagged by fishing line), Aquanotes (or wetnotes) and a pencil, a whistle and for most open water dives a safety sausage and safety spool. I would probably add a torch to that list too but tend to only take these on night, or limited visibility dives (along with a strobe, which is more effective as a surface marker at night than a static light). This is obviously in addition to basic items like a depth gauge/timer (computer) and compass. General safety gearI carry an open cell safety sausage as a surface marker and for deployment from depth. I've added a Extreme Exposure safety spool with 150 feet of cave line to my kit recently (in the left accessory pocket). A spool is important for overhead diving but also useful in the openwater (as a buddy line between divers in low vis, for use in searches (as a snag line or to setup a search pattern), to maintain contact with an anchor line in low vis, as an ascent line to deploy a surface marker after drifting away from a mooring line and a host of other applications I can't think of right now). I'm also carrying scissors (Sea Snips) at the moment (clipped in a pocket). These serve as a backup cutting device but scissors are more effective than a knife for freeing marine life from fishing line or other entanglements. Wet Notes or Aquanotes are a more effective and versatile communication medium than a slate. Messages can be left for other divers by tearing out sheets or sent up with a buoy to alert surface support. You also have a virtually endless supply of writing space. LightsLights are a useful tool in most diving environments (and a standard peice of kit to a DIR diver). My backup light is not pictured here (I attached the backup light to the right shoulder strap in the same way as I used to have my strobe attached, several images on this site now show the backup light in place). I bought an Extreme Exposure Scout light to replace an Underwater Kinetics SL4 which flooded (sofar had two SL4's flood). Scout lights are very simple and reliable and incredibly easy to fix if there is a problem. Most lights sold by dive shops are of poor quality and unnecessary complexity. The Scout light is compact, has a good beam, lasts for ages on a set of batteries and is virtually indestructible. My primary light is worn DIR style on the waist belt. I now own an Extreme Exposure Pro 6 10 watt HID primary light (the canister light in many of the images on this site is my old 50 watt halogen light (yellow canister and light head), I carry the new light in the same way). --> Canister light (Halcyon Pro 6 HID)
Specialist gear for research divingFor some types of survey work (eg. Marine Archaeology) a large slate or a lot of surveying equipment is required. To reduce clutter and make transporting lots of gear to and from a dive site easier I designed two research slates (Chad and Bob cut them out of tough material from a fume cupboard door (not laminex) from my template). The small slate is a simple double sided A4 slate but there is space for a photographic scale and tape measure to be attached (pencils are held to the slate by bungie cord, I don't like using strings to attach pencils, an entanglement risk). The large slate is designed to take up to three A4 survey sheets (or one A4 and one A3) on one side, the other side has a large elastic pocket for tape measures, camera and other accessories. There are loops for large measuring rods or frames to be carried. The large slate can be easily carried by one diver and both slates work like manta boards in the water (generating lift as you swim along). This seems a much more logical approach than attaching a stack of gear to my harness or carrying a catch bag or dragging a washing basket full of gear around.
The combination of a light weight streamlined float and thin cave line should significantly reduce drag (common to other float designs)... I have recently ordered a new surface float to use for drift and research diving. Or in other circumstances where a surface marker is desirable. On advice from George Irvine I am buying a Riffe spearfishing torpedo float and attaching/deploying it with a reel and cave line. The combination of a light weight streamlined float and thin cave line should significantly reduce drag (common to other float designs). This style of float may also be carried and deployed from depth. I will include pictures of this setup as soon as the float arrives. For some underwater mapping applications I use a foam torpedo float with a surface mounted GPS unit (in waterproof housing - Pelican). For accurate position fixing I use cave line with two metre increments marked to allow exact calculation of position based on depth, length of line to GPS and bearing. For general mapping applications I use bungie cord on the reel so I can change depth a little without having to reel in or let out line (useful in the shallows). I synchronise the GPS with my computer so I can link depth with location and use the computers bookmark function to include information about bottom type and the location of digital images of the bottom. Where to get gear in AustraliaThe following table lists useful accessories and the Australian suppliers.
Here are some more links that may prove useful to anyone interested in DIR diving.
Many thanks to everyone who's provided feedback or comments sofar. Certainly been a worth while exercise. Not only do these pictures allow me to get feedback from people who dive this kind of setup (no possibility of that locally) but also I've never seen what the setup looks like when I'm wearing it (makes it easier for me to recognise problems). |
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This page developed and maintained by Simon L Hartley Last updated 4tht March, 2002 URL http://www.scu.edu.au/schools/rsm/staff/pages/shartley/projects/gear/ |