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Good points made. My buddy diving plans are the same as yours. My shallow solo shore dive plans are much less intricate-- out to the left, over to the middle, back in.Yup, and there are some AOW divers that can plan dives as good as any technical diver. So what! You're arguing from a logical position called the missing middle. My first sentence supplied the other half of that logical construct. Exceptions don't prove anything. In fact, if anything, they disprove common misconceptions. The missing middle is that the vast majority of AOW or recreational divers can plan dives. But, the issue is what constitutes a plan?
I can tell you from my own experience as a recreational diver who's come up through the ranks (I'm a master diver now) that most of the dives I planned with occasional buddies consisted of: (1) who's going to lead the dive, and (2) where are we going (i.e. which end of the quarry, how deep do you want to go, or what do you want to see)? My buddies and I knew enough to watch our SPG's and surface with 500 psi. This idea that we should plan dives down to the tiniest detail is simply the result of higher trained divers projecting their own biases toward rec divers in out-of-context scenarios. Now, the dives I'm talking about are typical rec dives that don't include overhead environments or tasks that depend on minimum bottom times. For those dives some minimum gas planning and more detailed planning should be done.
Some posters in this thread have argued that beginning divers should know more about the inner workings of their PDC's. While I agree that some extra knowledge is helpful I would emphasize it is not necessary. What is essential is understanding what the display of the PDC is telling you. This argument for knowledge that goes beyond a minimum amount of knowledge required for safe rec dives reminds me of this analogy:
Most, if not all of you, reading this drive a car. How many of you look at the dashboard of your car? I would bet dollars to donuts you know what the gauges and idiot lights tell you. But, do you understand the inner workings of your engine to appreciate what those instruments are telling you? Automotive engineers do. So, the argument directed against new or inexperienced divers to learn the theory behind their PDC to be a safe diver is like an automotive engineer telling you you don't understand your car well enough to drive it safely.
I think people, myself at least, are advocating that new divers understand the very basics of NDL: the amount of nitrogen the body is absorbing is affected by pressure. Go up, and your body absorbs more slowly. Go down, more quickly. (yes that is a crude oversimplication, but I think it suffices). Tie that into the NDL time remaining (or a bar), and they basically have what they need to know to dive more safely.
I think people, myself at least, are advocating that new divers understand the very basics of NDL: the amount of nitrogen the body is absorbing is affected by pressure. Go up, and your body absorbs more slowly. Go down, more quickly. (yes that is a crude oversimplication, but I think it suffices). Tie that into the NDL time remaining (or a bar), and they basically have what they need to know to dive more safely.
Yup, and there are some AOW divers that can plan dives as good as any technical diver. So what! You're arguing from a logical position called the missing middle. My first sentence supplied the other half of that logical construct. Exceptions don't prove anything. In fact, if anything, they disprove common misconceptions. The missing middle is that the vast majority of AOW or recreational divers can plan dives. But, the issue is what constitutes a plan?
I can tell you from my own experience as a recreational diver who's come up through the ranks (I'm a master diver now) that most of the dives I planned with occasional buddies consisted of: (1) who's going to lead the dive, and (2) where are we going (i.e. which end of the quarry, how deep do you want to go, or what do you want to see)? My buddies and I knew enough to watch our SPG's and surface with 500 psi. This idea that we should plan dives down to the tiniest detail is simply the result of higher trained divers projecting their own biases toward rec divers in out-of-context scenarios. Now, the dives I'm talking about are typical rec dives that don't include overhead environments or tasks that depend on minimum bottom times. For those dives some minimum gas planning and more detailed planning should be done.
Some posters in this thread have argued that beginning divers should know more about the inner workings of their PDC's. While I agree that some extra knowledge is helpful I would emphasize it is not necessary. What is essential is understanding what the display of the PDC is telling you. This argument for knowledge that goes beyond a minimum amount of knowledge required for safe rec dives reminds me of this analogy:
Most, if not all of you, reading this drive a car. How many of you look at the dashboard of your car? I would bet dollars to donuts you know what the gauges and idiot lights tell you. But, do you understand the inner workings of your engine to appreciate what those instruments are telling you? Automotive engineers do. So, the argument directed against new or inexperienced divers to learn the theory behind their PDC to be a safe diver is like an automotive engineer telling you you don't understand your car well enough to drive it safely.
I agree that new divers should learn the basics of nitrogen absorption and its relationship to NDL. However, I don't believe it makes them any safer than divers who don't know those basics. Compare two divers: one who knows the basics and the other who knows nothing except what the NDL display is telling him. To be clear, the second diver knows to go shallow before his PDC's NDL display counts down to zero but doesn't know why. Let me ask you this: How does the second diver's safety differ at all from the first diver who knows the basics? They both make the same dives and both dive to the same NDL.
I have zero sympathy for NFL players with head injuries. Clearly there is a good deal of risk involved in making millions of dollars by smashing your body into other armored people for a living. Otherwise, the job wouldn't pay millions of dollars. I'm not saying they deserve it or anything but they really should expect to be injured after playing professionally for a few years. Next, we'll have fighters complaining about cauliflower ear after getting punched in the head a zillion times.Maybe. At a first glance, I'd say no as well, but it's really an empiric question.
As a counterpoint, consider helmets in American football. There is some ongoing research (and of course, controversy) about helmet use in the sport. The helmets are designed to reduce skull fractures, but are commonly believed to reduce concussions as well, which they don't. In fact, the research has the counterintuitive result that concussions have increased since helmet use became widespread. It could be due to the way the helmet changes the physics of a head hit, but this is unlikely. The most likely explanation is that hard helmets have given players a false sense of security, which has lead to more aggressive and dangerous behavior, hence the increase in concussion rates.
This is quite analogous to the question posed by the OP, and to your example of seat belts. I don't know the answer to any of the 3 cases, and if I were a gambling man I'd say computers are overall helpful (I use one myself, after all). My point is that questions like these are deceptively deep and complex, sometimes the obvious-looking answer ends up being incorrect.
I think that depends on agency and instructor choice. When I did my NAUI OW class about 5 years ago, we had to use tables for every dive. The class gear had AI dive computers (sherwood wisdom I think), but we used them as gauges.Most new divers have never had a table in their possession to make that connection.