Sport Chalet Instruction...new rules

[neil]

What does it matter if someone uses a table, wheel, eRDP, or computer to get the information needed to plan their dive as long as they are planning thier dive?

At some level I suppose it doesn't matter, but the diver won't have all possible tools available if they don't learn to use tables.

I think it's valuable to be able to conceptualize dive information in a more analogous fashion than just numbers, if that makes sense. Let me try to explain;

A digital watch tells you the time by showing you a number. That number by itself has no relation to any other time. An analog (one with hands, kids) watch shows you the time, and by it's nature indicates how much time has passed, and how much time there is until another time.

The eRDP and computers are digital watches. Tables are the analog watch. To me, at least, understanding where the numbers come from makes more sense. To students, I can only explain the numbers on their computers by correlating them to table info. And drawing dive profiles on the whiteboard.

I think the eRDP is an unnecessary and possibly confusing intermediate device. If you can work tables and do 2nd grade math you don't need it. My 2 cents, and worth every penny.

 

[rakkis]

At some level I suppose it doesn't matter, but the diver won't have all possible tools available if they don't learn to use tables.

I think it's valuable to be able to conceptualize dive information in a more analogous fashion than just numbers, if that makes sense. Let me try to explain;

A digital watch tells you the time by showing you a number. That number by itself has no relation to any other time. An analog (one with hands, kids) watch shows you the time, and by it's nature indicates how much time has passed, and how much time there is until another time.

The eRDP and computers are digital watches. Tables are the analog watch. To me, at least, understanding where the numbers come from makes more sense. To students, I can only explain the numbers on their computers by correlating them to table info. And drawing dive profiles on the whiteboard.

I think the eRDP is an unnecessary and possibly confusing intermediate device. If you can work tables and do 2nd grade math you don't need it. My 2 cents, and worth every penny.

Great analogy

 

[Thalassamania]

A digital watch tells you the time by showing you a number. That number by itself has no relation to any other time. An analog (one with hands, kids) watch shows you the time, and by it's nature indicates how much time has passed, and how much time there is until another time.

That's why I always liked the tissue bars on the EDGE.

 

[D_B]

I like the graph feature in mine as well. One of the more useful changes in the scan tool we use to check vehicles is the graph feature, it's way easer to monitor for changes while driving. The mind is geared to wards vision and visual cues , it is much easer for your brain to figure an image, rather than a number .. thats why the round gages being replaced by flat panels on aircraft, are reproduced on the flat panel as ... round gages (albeit with numbers included in the center)
I can see how you can get a visual cue from the dive table, and I still have mine and have used them, but I like my computer better, it has visual cues too

 

[Scot M]

I liked learning tables. I understood them intuitively and they helped me grasp basic decompression theory quickly. I assumed that tables were helpful to everyone right up until I taught my first open water class. That's when I discovered that most people struggle to understand data presented in a tabular format, even if they understand the underlying principles. I spend more time teaching, reviewing, remediating, and practicing the tables than I spend on any other single topic. Maybe I'm just a crap instructor, or maybe it's a sign of the computer-driven times, but learning to work the tables takes up a disproportionate amount of class time.

The next thing that happens to those brand new divers is that they take an advanced open water class and discover that tables don't really work for the multi-level dives we do in the real world. They quickly learn to rely on their computers for dive planning and monitoring, like most of the rest of us recreational divers.

I'm not a big fan of the eRDP. It could be sturdier and simpler to use, but I think that most students are going to have an easier time with it than with the traditional RDP tables. That's going to free up a chunk of time that I can use to teach them more about topics that will be relevant to most of them long after their tables are relegated to the bottom of their dive bag.

 

[The Chairman]

[Sarcastic inference]So do you teach people to use their buddies computer?[/inference]

I teach people that their best backup in the water is their buddy. If your depth gauge craps out... end the dive and STICK BY YOUR BUDDY.

If your watch craps out... end the dive and STICK BY YOUR BUDDY.

If your regulator/air source craps out... end the dive and STICK BY YOUR BUDDY.

if your SPG craps out... end the dive and STICK BY YOUR BUDDY.

and, in the same vein: If your computer craps out... end the dive and STICK BY YOUR BUDDY.

Of course the only way to really accomplish this was to have stuck with your buddy from the very beginning. Hopefully you are not suggesting that we should avoid having biddies or sticking with them. They are your best redundancy in an Open Water situation.

Please show me anywhere in this discussion where I have been inconsistent in recommending that you END THE DIVE in case of a primary equipment failure?

That being said, what do you suggest in any of the afore mentioned events? Please, I would love to hear what you recommend for these.

[Sarcastic insinuation][/Sarcastic insinuation]


Pete, you should chill a little in the inferences and insinuations. It tends to annoy doesnt it

Dude, there is no inference or insinuation in my remarks. They are as direct as I can possibly make them. I surely don't mind showing you just how fallacious and condescending your reasoning is. Take your OWN ADVICE and take a chill pill. Trying to misrepresent what I am saying does nothing to further your arguments and your continuing "insinuation" that I am teaching people to dive in an unsafe manner is not appreciated. You stop throwing darts at me, and I can relax a bit.

 

[The Chairman]

What are some of the advantages that dive computers have over tables?

Reality vs fantasy. One of the first things I learned from my trusty Cobra (now retired) was to do a safety STOP instead of a safety pause. I also learned that my ascent rate was WAY TOO FAST. How did this happen? I analyzed the data from my DC. If you had asked me before, I would have SWORN that I ascended slower than molasses and did a longer than necessary safety stop. The reality was in the download. This is GREAT feedback for any diver, new or otherwise. They can SEE graphically just how they dive, including their depth control and just how loaded they are during their dive with Nitrogen. Some DCs have the ability to see what is happening with the various tissue groups and I would like to see more of this. The "Computers rot your Brain" crowd overlooks this in their quest to rationalize their devotion to the archaic skill of "tables".

A graphical representation, rather than an esoteric representation of N₂ loading. I wonder how many people in this forum have a letter representation for the gas that's in their car. "Hey, I'm a "B" driver, I need to go add some gas to this pig." no, we rely on an ANALOG meter so we can see at a glance if we have enough gas to get home. Tables are counter intuitive, which is WHY so many have such a problem learning them. At depth, the diver can see his N₂ load creep higher and higher. He can see his bottom time expand as he ascends and plummet as he descends. This is instant feedback for the new and not so new diver. The best part? On many models of DC, you can plan various dives using their software on your home computer and see the same thing from the comfort of your own home.

Alarms. I have yet to see the table that will flash or beep you when your N₂ loading is getting dangerously close to your NDL. I got 2 1/2+ hours on my single HP120 last night on our New Years Eve dive at Weeki Wachee. Now, this was more of a working dive for me, and since I wanted to be ultra conservative, I left my computer set at 21% instead of dialing in the %40 NitrOx I was diving. I started my last 45 minute dive with only 1500 psi in my cylinder. I had just finished the last staged picture for the underwater cameraman and was cleaning up the various cyalumes we had denoting the underwater limits for the celebrants. I knew I was getting CLOSE to my limits (I check them at less than 5 minute intervals), but as I was descending to retrieve the "deep limit" marker, first the pressure alarm went off and less than a minute later, the NDL warning went off. I snipped the marker and went to do my 5 minute safety stop. So? Well, during the entire time, I was preoccupied by the 50+ divers in the water. An entanglement here, a free flow over there, a rototiller to my right. This was work to keep everyone safe and maintain the integrity of the limits. I was happy that I had those alarms JUST IN CASE I became preoccupied with a rescue or something.

Diver acceptance. I'm sorry. But I either see divers with a computer or with NOTHING. I simply don't see tables on the boats or the shore. In fact, when tables do come out, many divers make the observation about how unusual it is to see them. Cost is less of a factor nowadays and divers simply avoid using tables to their own peril. This is an out and out rejection of these tables, except by a few (mostly tech) divers.

 

[neil]

Maybe I'm just a crap instructor,

Possible, but only you'd know that.
Seriously though, one of the problems might be with how the tables are presented. For PADI, it's late in the series of modules (third?) and basically all at once. Try teaching the tables early and often: table one the first night, review of table one and table two the second night, etc. A student doesn't even need to understand (yet) the underlying principle to simply work the numbers. This works for me. It seems a lot less intimidating when broken into smaller chunks.

 

[MikeFerrara]

What are some of the advantages that dive computers have over tables?

Reality vs fantasy. One of the first things I learned from my trusty Cobra (now retired) was to do a safety STOP instead of a safety pause. I also learned that my ascent rate was WAY TOO FAST. How did this happen? I analyzed the data from my DC. If you had asked me before, I would have SWORN that I ascended slower than molasses and did a longer than necessary safety stop. The reality was in the download. This is GREAT feedback for any diver, new or otherwise. They can SEE graphically just how they dive, including their depth control and just how loaded they are during their dive with Nitrogen. Some DCs have the ability to see what is happening with the various tissue groups and I would like to see more of this. The "Computers rot your Brain" crowd overlooks this in their quest to rationalize their devotion to the archaic skill of "tables".

Actually I know a lot of the "computers rot your brain" crowd who use computers in guage mode just so they have that download capability. It's not worth the extra money to me but I have some nice graphs on my PC someplace that a friend sent me of some fairly deep cave dives we did together.

Still, there's no reason for a diver to not know what his real ascent rate is if they are taught how to guage ascent rate.

A graphical representation, rather than an esoteric representation of N₂ loading. I wonder how many people in this forum have a letter representation for the gas that's in their car. "Hey, I'm a "B" driver, I need to go add some gas to this pig." no, we rely on an ANALOG meter so we can see at a glance if we have enough gas to get home.

That's not really how letter designations are used is it? They aren't used in the water at all and, out of the water, they are just an intermediate step to getting the adjusted "no decompression time" for the next dive. "Time" can easily be tracked on an anolog meter during the dive using an inexpensive watch.

Tables are counter intuitive, which is WHY so many have such a problem learning them.

First of all, I don't think tables are counter intuitive but second, they sure aren't anywhere near as counter intuitive as the menue structures and set up procedures of some of these convoluted computers. Thirdly, I think all this supposed trouble people have learning them is a myth. The only people that I've ever seen have trouble learning them were the people who refused to read any class material before comming to class...so the class format had to be changed to accommodate them. I remember one student who owned his own accounting firm. You'd think he could handle a table wouldn't you? Accounting is nothing but tables. He just didn't want to do it and his remark was..."Isn't that what the DM is for?" Still, even when I had to teach tables without the benefit of the student having read the book, I don't recall ever having a problem...aside from not wanting to spend class time doing it.

At depth, the diver can see his N₂ load creep higher and higher. He can see his bottom time expand as he ascends and plummet as he descends. This is instant feedback for the new and not so new diver.

Well you already know that right? Don't we know that we can stay at 40 ft much longer than we can stay at 100 ft without a live graphical display?

The best part? On many models of DC, you can plan various dives using their software on your home computer and see the same thing from the comfort of your own home.

That is a nice feature and I have lots of software for both my home computer and a palm that lets me do just that...only I didn't need to buy a dive computer to get it.

Alarms. I have yet to see the table that will flash or beep you when your N₂ loading is getting dangerously close to your NDL. I got 2 1/2+ hours on my single HP120 last night on our New Years Eve dive at Weeki Wachee. Now, this was more of a working dive for me, and since I wanted to be ultra conservative, I left my computer set at 21% instead of dialing in the %40 NitrOx I was diving. I started my last 45 minute dive with only 1500 psi in my cylinder. I had just finished the last staged picture for the underwater cameraman and was cleaning up the various cyalumes we had denoting the underwater limits for the celebrants. I knew I was getting CLOSE to my limits (I check them at less than 5 minute intervals), but as I was descending to retrieve the "deep limit" marker, first the pressure alarm went off and less than a minute later, the NDL warning went off. I snipped the marker and went to do my 5 minute safety stop. So? Well, during the entire time, I was preoccupied by the 50+ divers in the water. An entanglement here, a free flow over there, a rototiller to my right. This was work to keep everyone safe and maintain the integrity of the limits. I was happy that I had those alarms JUST IN CASE I became preoccupied with a rescue or something.

A matter of opinion I guess. I haven't seen any evidence that computer alarms have provided any functional advantage.

Diver acceptance. I'm sorry. But I either see divers with a computer or with NOTHING. I simply don't see tables on the boats or the shore. In fact, when tables do come out, many divers make the observation about how unusual it is to see them. Cost is less of a factor nowadays and divers simply avoid using tables to their own peril. This is an out and out rejection of these tables, except by a few (mostly tech) divers.

I think this has a lot to do with the "sales job" I mentioned earlier in the thread. Even if they learn to use a table in the classroom, most are NOT using table to plan their actual dives even in training. They get out of the water and get their numbers from their instructor who is using a computer. The "computer" idea is put in their head from day one. They're essentially being taught to follow the DM or follow the lights from day one. If there's any one single group who could easily do without a computer it's new divers who are diving appropriate depths.

 

[MikeFerrara]

Possible, but only you'd know that.
Seriously though, one of the problems might be with how the tables are presented. For PADI, it's late in the series of modules (third?) and basically all at once. Try teaching the tables early and often: table one the first night, review of table one and table two the second night, etc. A student doesn't even need to understand (yet) the underlying principle to simply work the numbers. This works for me. It seems a lot less intimidating when broken into smaller chunks.

I know I've said this before but it's not my experience that students really have trouble comprehending the tables. They are about as simple and atraight forward as a thing can be and they usually have the simple instructions printed right on them for quick easy reference.

If a student really did have trouble comprehending the simple steps involved in using a table I'd be concerned about their mental fitness for diving and would probably be inclined to suggest they get the opinion of a medical professional or at least someone who is more qualified to diagnos and assess learning disabilities than I am. As I say though, in the cases where I had students come to class not familiar with basic table procedures, it was a clear case of not having read the book. They're going to have even more trouble with their computer if they refuse to read the book.