Another Tables vs. Computers Thread

[MikeFerrara]

No, but the tables sure have them, don't they?

No

Why blame the dive computer for a diver's lack of skill? This is nothing but a red herring put out by a few. At worst it is nothing more than a fallacious appeal to fear. Unless of course, you can prove that table divers have better buoyancy skills than computer divers.

Can't blame the computer. I don't know if it's an appeal to fear so much as a reaction to it. I've seen enough things happen enough times including some injuries that I am very afraid for many new divers and some old ones too.

Using a watch and a depth gauge is FAR MORE TASK LOADING than just the ascent rate. I would say it's over 4 times as much (two instruments plus the mental gymnastics) task loading that may lead to a less than timely adjustment on the BC. But that's what the novice diver needs, right? Let's add even MORE task loading!

No it's not more task loading. The ability to ascend a short distance, stop and stay there makes one about as easy as the other. Divers trying to respond to an ascent rate display usually just alternate between too fast and too slow with the overall ascent rate being way off with maybe even some descents tossed in. In the mean time they're staring at their computer instead of keeping an eye on their buddy which is bad because ascents are amoung the riskiest periods of the dive. Go up a little and stop for a time...move up again...stop again. You can go up that litte bit about as fast as you please within reason and whether you dive tables, computers or use ratio deco, you don't need an ascent rate display.

This simple skill is, IMO, exactly what a novice diver needs.

 

[limeyx]

No, but the tables sure have them, don't they?
...
Using a watch and a depth gauge is FAR MORE TASK LOADING than just the ascent rate. I would say it's over 4 times as much (two instruments plus the mental gymnastics) task loading that may lead to a less than timely adjustment on the BC. But that's what the novice diver needs, right? Let's add even MORE task loading!

I dont think anyone said "Let's go out and make all new divers use tables/bottom timers and/or calculate profiles in their head"

In fact, that *would* be unsafe because it does take experience and practice and good buoyancy skills (which divers ought to be striving for anyway). I believe I said exactly the opposite -- that I hope my comments here do NOT convince divers to throw away their computers.

However, not using a computer or a printed table during a dive *is* possible and can be safe if done properly, and I think it can be useful to get people thinking a little about what their computer is really doing and telling them underwater.

Ok, this Is (I hope my last post here. I think we've beaten this to death.

 

[The Chairman]

Divers trying to respond to an ascent rate display usually just alternate between too fast and too slow

Then you have not taught them correctly. Teach them how to use the tool in situ.

 

[MikeFerrara]

Then you have not taught them correctly. Teach them how to use the tool in situ.

Why don't you give us a quick explaination of how to use or teach them correctly?

 

[The Chairman]

There are three (3) bars that show how fast you are ascending. I simply show them how to become slightly negative as they begin that final ascent. Watch the bars. One is great and two is OK, but that third bar means you are ascending too fast. It's a simple bio-feedback. At any time they are ascending without kicking, they need to deflate just a bit... so they don't see more than two bars at a time. After the 5 minute safety stop they should never see more than one bar as they ascend. Simple, simple, simple. This applies to the VEO250, which is what my OW students learn on.

 

[MikeFerrara]

There are three (3) bars that show how fast you are ascending. I simply show them how to become slightly negative as they begin that final ascent. Watch the bars. One is great and two is OK, but that third bar means you are ascending too fast. It's a simple bio-feedback. At any time they are ascending without kicking, they need to deflate just a bit... so they don't see more than two bars at a time. After the 5 minute safety stop they should never see more than one bar as they ascend. Simple, simple, simple. This applies to the VEO250, which is what my OW students learn on.

As you can probably guess, I disagree with teaching (or using) a negatively buoyant ascent or any vertical ascent. If you're kicking to ascend that probably means you're vertical and I see all kinds of problems with both. A few would include but not be limited to... if you're distracted by another task and stop kicking, you sink...the same problems as not being neutral at any other time during the dive. kicking should mean going forward or backward but shouldn't be required to maintain depth. If you're vertical it's much harder to maintain a constant distance from a buddy and if you have to get to them in a hurry, you have to change position before you can even swim forward... as apposed to ascending in a horizontal position where forward and backward finning is used to maintain distance and you're in the best position to be able to move in any direction...one stern kick will put you right in your buddies face, where you may need to be in a hurry if he has a problem. You probably never heard or read me saying this before but ascents and descents are two of the most dynamic portions of the dive where problems are more liky to happen and divers need to be the most prepared to respond.

And yes, OW students can learn to do a pretty good horizontal ascent BEFORE going to open water in, what I would consider, a reasonable length class that provides the classroom information needed and a little practice time in confined water. I can't say that many got very good at finning backwards but that's easy to get around. And no, this isn't a comment about the length of your classes because, I have no idea how long your class is.

In the old days before the BC, I guess you had to fin up. Fortunately it's a problem that can be fixed now the we have the BC...as soon as the agencies figure out what the device is for and how to use it.

How fast is one bar? Do you teach other ascent techniques that don't rely on bars? If so, good thinking. If not how do your students adapt the technique you teach in the event that they end up diving using a computer that has no bars or with rental equipment somplace where there aren't any computers at all. I'm sure rental computers are more common than they used to be but I doubt they're available everyplace or that all computers have bars.

 

[The Chairman]

I see no compelling reason to teach a horizontal ascent to a student. Though I have had students mimic mine.

I teach them to use the tools they have at hand. I also teach that they should become familiar with any new gear that they purchase, rent or borrow.

Depending on depth. Under 60 fsw, 2 bars= 60fsw/min. Above 60 fsw, 2 bars= 30fsw/min.

 

[Blackwood]

It seems to me that an adequately trained diver would have a good understanding of buoyancy. They wouldn't need to be taught HOW to ascend flat out. Rather, they need only be instructed to do so (and why).

[/couple of cents]

 

[LSDeep]

Does that computer control the divers BCD?

surely not! but do your tables (if you use them instead of computer)? bad / nonexistent divingskills are an absurd argument in this (useless - cause nobody will cave in) discussion! you dont learn how to dive with or without computer. skills are still aquired in your course/s with your instructor. maybe one day (i cant see it yet) computers will do all of it for you - its not happen yet! you still learn to dive and how to use support tools, that might be tables / computers or whatever. dont blame technology for inability. its like blaming a car gps for the crash because i turned at the corner it indicated and there was another car i run into.
why do i post here still? its the old, never to be settled in endless threads "need to know everything including developing tables vs. use whats available to the best of your knowledge and available technology (and creditcard)" argument.
you dont learn diving and needed skills from using tables or computer and neither makes your ascends or decends and dives better if you are clueless. they are tools to stay in top of your activities (whom you trying to blame if you get a speeding ticket? - your car or your leadfoot???).
it seems hard for some to adopt new "technologies", so go ahead and use the ways you learned way back and ignore it. i am sure you will start also soon to mail your replies to threads here in by snailmail and see them month later published if somebody bothers to type them in for you.
its the first i dived on air and that was good syndrome. than came nitrox and i had a hard time to accept it (even more so with trimix). but i had my tables!!!!! and all was good because with them and my formulas i was save (wonder why - you must have been part of the development team and seen the chambers often). next there came this tech nerds and claimed its all easier with this silly little screens on their arms and they MUST BE stupid lunatics. after all, we never did it like that before!
you have an issue mow with computers in diving and the "dont know the background" argument? - i would suggest to slowly start selling your gear and take up a new hobby. it will get worse!
rec divers will (and do already) take their classes online entirely and see you first for poolsessions and dives. they will still know why their computer works in a certain way, like they did with the tables. they will still not be able after an open water class to explain to me (or you) why it is like that and what the entire "science" behind it is to make it happen. its a math model somebody worked out - and it works. amazingly enough. your bcd will possibly still not be controlled by your computer or table and it still doesnt matter to have you comne up after a dive healthy and safely. people will still have probs to clear their mask and the computer will still not help - we are working on it, to "dumb the courses down" further.

the idea should be to teach diving with safety in mind and the latest available tools people are known to commonly use. everything else is just teaching history. kinda like i teach you how to use a pc with a dos system instead of windows this days (no pun for mac users).
should we start to lobby that pc's on schools should be forbidden, cause kids dont lern properly how to write with a pen? - it would poss make more sense than the whole tables vs. dc discussion, but will not be happen anymore.
whats the next argument - tanks vs rebreather? fins vs. scooter?

................ so much more to write and so little time! sorry have to abort that now to go diving (with a computer ), later more after i killed myself not calculating my dive with tables first

 

[MikeFerrara]

I see no compelling reason to teach a horizontal ascent to a student. Though I have had students mimic mine.

The advantages I listed above is what compells me.