I had the opportunity to compare and contrast my 3 favourite canister lights this weekend, all by Diverite, the 10w HID, the LED500 and the new LED700. LED technology is receiving a lot of focus and the light they emit in diving use is clean, bright and white, as is that of the HID units. There was not a lot in it between the 3 lights, tested in the pitch dark at a depth of 140'. The 10w HID is a narrower beam than the LEDs and the LED700 was, it seemed, every bit its equal in terms of brightness, whiteness, intensity and penetration and is a broader beam. The LED500 was a shade behind these two in terms of brightness but in fairness the batteries were not new and had been on several dives- testament to the long lived delivery from this light (13 hours from 8 AA batteries!)
My preference is for LED. I am hard on my equipment, am not as diligent as I could be in looking after it and still expect it to perform flawlessly. I have had several HID systems and sooner or later the bulb goes and these are not at all inexpensive to replace. I have all 3 of the above systems and my HID will be sent in for an LED retrofit once this bulb blows.
The LED500 is, I find, an excellent primary in its own right and extraordinarily good for travel. Weighing in at only a few ounces it uses widely available AA batteries (8) and lasts an age on them.
We have yet to touch on backup lights. More about lights etc on the course.
Train Right.
If you are reading this then you will not need another 'why trimix' blog- you will know that already. So how do we do it? With hypoxic mixes, we typically carry a travel mix (which could be a deco mix) and, as we will have a high %He in the bottom mix, might typically carry an intermediate TMx to switch to at a predetermined depth dusring ascent.
For the mathematicians among the readership it will become apparent that we will likely have 3 or 4 stage cylinders slung on us- more sometimes. There are various methods of carriage and management that we cover during the course and needless to say that correct gas management becomes paramount.
There are many issues associated with depth that need be addressed, crushing of gauges, battery packs, etc being some of those readily addressed by the appropriate gear- see Required Equioment for details on that.
Train Right
Students reach for Tec 1 for a variety of reasons, to learn more, to dive better, just out of curiosity, or to fully embrace technical diving. The certification and experience levels of those who attend are very diverse and range from new, Advanced Open Water divers with the bare minimum of dives through to instructors and technical divers certified through other agencies and all of them, including the latter two especially, say that they learn a lot on the Tec 1 course. Which is just as well as I tell them that if they do not, then I will refund them their course costs- I haven't had to do that yet.
A fresh Tec 1 course starts this evening and one of the students is an experienced and well certified instructor- I am confident that I will not have to write a cheque to refund the course costs!
Train Right!
The multi level specialty seems to be one of the less common specialties which is a pity as, properly taught and executed, it is a truly first class one and so very useful for aspiring technical divers.
Rather than leave everything to the computer (read 'to chance' for that) the technical diver plans the dives in advance; planning various depths and the durations spent at each depth, the gas required at each level, the toxicity etc. So it is with the multi-level specialty diver. It is just that the depths and gases may be different- the core foundations of the planning process and execution of the dives remain the same however
The multi level diver plans dives with 2 or 3 distinct levels each within NDL and cumulatively within overall NDL but which, if planned as a square profile, could result in significant decompression obligations. The result is that multi level divers are still in the water enjoying their dive when others are out and waiting for their surface interval to expire!
IMPORTANTLY, multi level divers can then PLAN their second dive as a multi level dive (rather than the computer user's plan which is a square profile dive)- again this translates into knowingly undertaking a longer dive than might be otherwise done (rather than again computer users jumping in and seeing what they get). The result is that the ML diver knowingly plans for and executes longer dives than other divers and on a trip this can result in more dive time for your $ spent- think on that. You spent a lot of money to go to dive some exotic location, doesn't it make sense to maximise your time diving rather than having shorter dives? More dive for the $. And if the dive is planned and executed using nitrox- it is extraordinary what can be achieved in terms of dive times and repeat dives.
Email Paul at info@technicaldivinginstructor.com to arrange for a multilevel specialty class, or any of the classes for that matter. The ML class is enormously rewarding on many levels (no pun intended) and great fun, too- you will not regret doing this one at all.
Tec to Rec how tec techniques can benefit the recreational diver 09/05/2008 0 Comments Recreational divers can benefit on many levels by adopting some of the technical diving lessons. This note is intended to outline a few of these.
Regulator.
Almost the hallmark of the technical diver (after doubles and stage cylinders) is probably the ‘long hose’. In overhead environments (wreck and cave) a 7’ hose is de rigeur but in open water a 5’ or 6’ hose is very useful. In an out of air situation the long hose is donated and the secondary is breathed by the donor. In a recreational setting, imagine how much more comfortable and thus relaxed (which in an emergency is a good thing) divers would be if, while air sharing, they did not have to be inches away from each other limited by a short hose length, but rather could enjoy the luxury of separation to within their comfort zone depending upon the situation. Stowage of the long hose is easy, comfortable and not in the least cumbersome.
If using a true octopus as a secondary, rather than a hybrid inflation/ air source (such as the Scubapro Air2) then hang the secondary by a necklace around the neck (and under the chin- not way down by the chest) just as a technical diver hangs the secondary regulator. This ensures that when it is needed it is ready available- which those octo holders and other elaborate means of stowing this emergency device do not always allow. Note that the secondary is breathed by the donor (who has given away his 5’- 7’ primary) and so the secondary can be on a shorter hose than the traditional octopus making for a cleaner, less cluttered, safer setup altogether.
Redundancy
Technical divers have the philosophy of ‘two is one and one is none’ which may not be wholly relevant to the recreational diver, however some items might be beneficial to duplicate.
Gauges
Gauges might fall into this category. Whilst I am not necessarily advocating purchasing 2 computers, a backup to the computer such as a manual depth gauge and timing device might just save a dive if your computer fails as you gear up on that dive boat out at sea. If carried, ensure that backups are readily accessible and checked periodically during the dive otherwise their value is diminished in the event of requiring them.
Cutting tools
These are important diving items- especially if lines or ropes are anywhere near and having two of them will ensure that you always have one- even if you drop one. Cutting tools should be easy to deploy and stowed in the access triangle area of the torso. The enormous leg knife may look impressive but is of limited value if you cannot reach it when you need to. Similarly the hose mounted knives.
Lights
Lights are next. If only to save your night dive- carry a spare. Bulbs blow, and even with LEDs batteries die or lights flood. Both lights should be stored away and not dangling- bicycle inner tube is excellent for this purpose. Technical divers store backup lights either on the webbing straps UNDER the armpits, held in with inner tube pieces or in wet/ dry suit pockets. A small, powerful LED backup neatly stowed in this manner is never a burden and can always be carried for those moments when it will serve unexpectedly as a primary light.
Other Gear
Technical divers are noted for their gear, much of which has excellent crossover potential to the recreational diver.
Reels
Reels can be extremely useful in low visibility diving but divers should be properly trained in their use as line and water are a potently dangerous mix- especially if visibility is very low and the diver is carrying the massive leg strapped machete previously mentioned. Reels should be small, reliable and robust. And their correct use should be properly trained, especially for low visibility diving.
Lift Bag
A safety sausage is one thing but a lift bag quite another. At around 50lbs of lift as a minimum, a lift bag has many uses from lifting recovered items from the floor to marking your ascent and a signaling device (safety sausage style). Lift bags are butt mounted on the BCD by simple elastic or surgical tubing loops keeping the bag out of the way and secure until required.
Technique
Buoyancy is, or should be, the mark of the technical diver. The ability to maintain neutrally positioned, horizontally aligned and static in both relative (near other divers of the team) and in absolute terms (eg maintain a depth whilst under task) is no small feat and is the core technical diving technique. Imagine the dramatic pictures the recreational photographer could take if able to hold position, back up, side slip and rotate as necessary to capture that elusive piscine moment. There is no substitute for this other than to receive training on how to achieve this zen-like ability.
Conclusion
There is much more that can be discussed as of crossover benefit but I leave that for another time. Brief and hopefully of value, I hope this has illustrated some of the ways in which recreational divers can benefit from developments of technical diving field.
Back to Basics 08/27/2008 0 Comments It is always worth going back to basics. In golf, we practice driving, in cycling (I race cycles, by the way) we practice pedal strokes, in rugby (scrum half is my position) we practice passing and in scuba we practice, or at least we should, basic buoyancy. Amongst other things it is mastery of the fundamental building blocks that marks the great from the good.
This is especially trus for divers. Maintaining position in the water column in absolute and relative terms is key to technical diving and is especially useful for photographers.
My students come away from the courses with the ability to maintain depth to within 24" whilst conducting drills and skills AND whilst maintaining position relative to the rest of the dive team. It takes some coaching and some application on the students' part but once they have it- they are masters of buoyancy and the more complex dives have suddenly become much easier for them.
Come and try the technical courses, you will not regret doing so and will learn enormous amounts in the process.
Side Mount- not just for cave divers. 08/21/2008 0 Comments Developed primarily for cave diving, with as many variations on a theme as there are sidemount (or SM, as it is abbreciated to) divers, SM can be used in open water environments and can be useful for those suffering from a bad back or for smaller divers where heavy twin cylinders might be a burden. Or for those just interested in increasing their scope of diving knowledge and practice, too.
SM requires a different approach to diving and its practice which it is best to receive guidance and instruction on. It is liked, indeed preferred, by many who try it for open water diving.
SM rig choices are few, and curremntly are the Armadillo, the Nomad or a lashup of ones own design, often called a Frankenrig or similar. All of which I have tried and can advise on.
If SM captures your imagination, drop me a line at info@techdivinginstructor.com
Tec 1 and Tec 2 (or Deep Tec) can be taught in SM.
Train Right
Jailhouse Diving 08/14/2008 0 Comments In Austin, TX Mansfield Dam forming Lake Travis is a popular dive venue for tech diving and recreational diving. It makes for a good place for tech diving instruction and training also. The dam has several sluice gates which are guarded by large concrete and iron bar structures designed to keep major debris (logs, boats, divers etc) out of the gates when they are opened. The vertical bars and concrete give the impression of a jailhouse. Diving them is interesting. These structures reach down to the gates at a depth currently, as the water level is low, of 140' or so.
These structures are not entirely open at the top and, to my knowledge have no exits in them creating a de facto vertical overhead environment.
The visibility was surprisingly good, the temperatues reasonably warm at depth and positively bath like shallower. Runtimes were modest with a small deco obligation on O2.
It was interesting to see my team mate's VR3 informing him to go to tables (previously cut using GAP) once he omitted the deep stop the VR3 wanted. Interesting software design, methinks.
Graduation-congratulations 08/12/2008 0 Comments The final dives of DSAT Tec 1 completed in Lake Travis, Austin, TX and tec diving instruction now over, the students look, talk and act in a manner very different from a short while ago in their pre- tech diving days. The final tec 2 dives were outstandingly good. The competence and confidence displayed in the deep sections of the water was extremely high as the dive team worked together to achieve their missions.
There are no words to sufficiently describe the feelings one has when diving with such highly competent divers working together as a tightly knit team. Beautiful!
Congratulations to Billy, Dave and Michael on graduating and doing a truly first class job.
Thirds 08/04/2008 0 Comments The following is meant to stimulate thought, not usurp training, not invite strong rhetoric, merely generate thought in the readership.
Tech training teaches the Rule of 1/3s as a matter of course (and 1/4s sometimes) and in an overhead environment such as a wreck or cave this well tried and tested system should not be trifled with by mere diving mortals, however in open water the strict adherence to the Rule of 1/3s might be questioned.
I am not talking about the contingency planning component of 1/3s here as in overhead environment diving. In open water tech diving planning you will run several 'what if' scenarios which would force consideration of how much back gas is being carried and would remain after the turn point and be available for contingencies.
What I am talking about is applying the rule of 1/3 in, 1/3 out, 1/3 reserve to open water tech diving situations. In open water tech diving, we will turn at 1/3 pressure (ie start to ascend) then at a certain depth we will switch to a stage gas and then switch to another at a shallower depth- so we did not need the "1/3 out" component from purely our back gas- we merely used from depth to switch level 1 as then we switched to stages. Again, do not confuse the issue with the purposeful contingency planning you will go through during your training with me. Thus if could be argued that we turn the dive early based on using 1/3s. Perhaps we should explore the appropriateness of the Rule of 1/3s for open water technical diving.
Think on that for a while.
Tec 1 08/01/2008 1 Comments Tec 1 is a powerful course. It teaches almost all of the skills, drills and practices a tech diver needs for progression to decompression diving and accelerated decompression diving at Tec 2 and then onto trimix diving. The major difference between successful completion of Tec 1 and Tec 2 (and Trimix) is the gases used. The skills learnt make highly competent divers.
The current Tec 1 class is 1/2 way complete and the students range from PADI AOW with a the minimum requirements to a NAUI DM with 500 dives, and in between- all of them are at the same level when it comes to Tec 1, they are all finding the content to be challenging, stimulating and greatly enjoyable. They are coming along really well.
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