Posted by seahunt on January 17, 2001 at 16:21:24:
In Reply to: A few more thoughts posted by MHK on January 17, 2001 at 12:52:41:
>>and I've spent a fair amount of time explaining why we do what we do.
Actually, ambiguity has been one of the biggest problems. I had to research
to discover what I thought were the important issues. You discuss streamlining
and backpacks a lot, but really, you skip an enormous amount. What you and the
DIR websites mostly focus on is backplate configuration and deep (gas
requirements and deep stops). There is no mention of computers or consoles,
though the steel/wetsuit is mentioned on George's site. Maybe that new
book will clear it up some. I also await your description of uw multi-level
deco calculations... see below.
>>For example, you cite the buddy system reliance
I have not really brought up the buddy system in my posts of the last months.
I thought it a good point to skip. It did not think it was determinate in our
current discussion. I did mention that I generally considered the buddy system
safer than solo.
>>You take issue with the suggestion that we don't recomend a console and this is a
>>disqualifying factor. Nonsense.. As you stated you don't use one,
Actually in my last post, I said that there might be a mis-understanding, because I
do use one and I described its configuration. Compass w/ SPG and computer/depth on
the other side. About the size of my fist.
>>*you used to dive twin 72's all the time absent a bc*
>>but then again by avoiding the practice and using AL with wetsuits and a drysuit
>>with steels it's an issue that I don't even have to concern myself with.. The problem is
>>solved before I get in the water..
But the best gear configuration I've found for hunting is a steel 100 w/wetsuit
I don't want to give up either. An Al 80 is just not enough air and an AL 104 is
huge. The Steel 100 and wetsuit gives me enough air and great mobility... Which
is what I consider most important for my diving. Why should I give it up? After
trade off evaluation, the added efficiency is considered worth the minor
(unconcious) loss of safety.
>>You take issue with our suggestion to eliminate the need for a computer by spending additional time
>>learning the decompression theories thereby avoiding the need for a computer.. You continually ignore the
>>fact that we keep saying over and over and over that if you lack the capability that you wrist mount the
>>computer, and then again cite this as a disqualifying factor..
(1)I repeatedly and graphically stated that no matter how good you are at calculations (and
I am very good) that it is not feasable for my typical profile. Tell me if I am wrong
about that, because that becomes a safety issue, not just convenience.
(2)I don't want to waste the precious time. I can do a reality check of the computer at the end of the dive
to see if there is any anomalous readings that might suggest computer failure. I have to do this anyway
to determine what my profile limits for my next dive are.
(3)I have continued diving after computer failure (both times my fault), but I had to then
follow the more conservative results that the tables give.
(4)Remember the capillary depth guages of yesteryear. That is the only guage that I have ever worn on my
wrist and I didn't like it. That's why I use a console. I find them convenient with no appreciable
drawbacks. Actually, for a long time I used a Skinny Dipper which is not console mounted,
but I was glad that my new one was. It's more convenient. I still used a console when I had
the skinny dipper.
(5)Don't bother asking if I am capable of learning deco models. I've forgotten more than most people ever
learn in their lives. At the same time remember. Many good divers (people) do not have good ability
to do calculations on the fly. It's just not in their nature. Thay can still dive just fine though and the
computer is a great aid for them... That's why computers are popular. Don't take computers from those people
especially.
>>Your logic is confusing, on the one hand you want to add all these potential additional failure points to a
>>dive and then counter with contingeny plans to offset the added risk but then you don't want to take the
>>time to learn the models thereby avoiding having to spend several hundred dollars on a computer..
Will you claim that you can re-calculate an erratic sawtooth profile over numerous dives and
multiple days near as accurately as a computer? Again, this is the same critical issue, because it
relates to safety. If you want to disagree with me, do it on this important point.
Learning the models better would still not allow me accuratly calculate deco requirements for an erratic
profile. As important, I don't want to take the time. It is not a matter of cost in money, it is time
uw and enjoyment.
A computer is far cheaper than a trip to the chamber.
>>You have failed in every material point that you have raised to indicate why DIR doesn't apply to west
>>coast.. Frankly, it seems as though you have invested a great deal of time and effort digesting the system
>>and the sum total of your objections simply don't rise to the level of a serious critisim..
Correct. DIR is a good system. It then becomes an issue of my arguement that the system, like
almost every other system on earth, can be adapted to local needs. The DIR system does not refuse this any
more than a car refuses to be repaired or customized. That is the contention of the DIR proponents. That
I have said, is very odd. Lobster hunting is pretty specialized and demanding... Besides, look at my comment
below about adapting the DIR system.
>>That choice is yours to make but it simply doesn't mean that DIR is less than adequate
>>for our diving..
Right, but it is less than optimal. I know a better system for my diving. We could all drive
a Honda Accord, but we don't. Some people need trucks. Some people want sport cars.
>>On the surface you point out that there are very many minor details within the DIR system that in all candor
>>seem insignificant at each level, but when coupled together ( ie; take the system as holisitc) they add up..
>>Dan Rostenkowski ( former Chairman of the House and Ways committee ) once said that you save a
>>billion here, you save a billion there and sooner or later your talking about real money..
The Jury is still out about the meaning of Holistic. It is not in all dictionaries and there is debate
about if its meaning is artificial. It is usually used in conjunction with ideologies like certain
experimental medical practices.
Holistic just means that the important components of something have not been analyzed yet. It just isn't
applied to engineering systems. It is contradictory to modern engineering practices. DIR does not trancend
engineering and its parts can be analyzed.
>>Well the same thing applies to DIR's mindset, you save a failure point here, you save a failure point there
>>and sooner or later you'll add up to a safer diver..
See, here you consider the DIR system part by part by part and then you say it is all one indivisible part.
I just want to add a part or two.
>>because it works at 400' means that it doesn't apply to recreational diving.. I'm baffled by that logic..
Specifically because a computer is useful at 60, but less so at 400. This is the same computer issue.
I would not expect to do a sawtooth profile at 400 feet. That is the difference.
>>you recall the resistance to embrace computer when they first were introduced.. The outcry was that
Not really. The Edges were prohibitively expensive at first, but the hunters really wanted them to extend
their bottom times. By the time we were using Al 80's and Steel 95's, a computer often meant at least
one extra tank per day.
>>Nitrox has withstood a firestorm of criticism only to be later viewed as beneficial
True, but it wasn't me. It was the shops and instructors. I dunno why??
>>even the bc was frowned upon initially by some..
Why people had trouble learning not to go for the BC elevator ride is beyond me,
but they did originally. I just considered them extra gear. I liked a simple backpack.
Eventually though, BC's got required on the boats.
>>In concluding as I noted above I believe that in summary our biggest difference is that you
>>are willing to begin a dive with added failure points
Computer, console and steel/wetsuit. Put it how you like. I choose them for their
convenience and functionality. Safety is not the only criteria I use and only the
steel/setsuit did you call a safety issiue. You should see some of the scary
stuff.
******************************************************************************************
Here are a couple of posts from you that I find most interesting.
Re: Not thinking it through http://diver.net/bbs/messages/7256.shtml
Reply to Jason.
You were not too concerned about a single steel tank with a wetsuit.
Well, OK. Apparently the DIR can be modidfied some.
***
This is your response to DiveBum
>>The reason for the added BT's when diving a computer is ...
Well, that sounds like an added BT from a computer...
****************************************************************************************
You have claimed that your system is superior in all ways.
I say that my system is better for my diving.
One element of your system is unsafe for my type of diving. No computer.
You have never even claimed (yet) that you could calculate a typical erratic sawtooth
profile that I use a computer for. I would doubt you if you did and I don't want to
waste the uw time calculating it anyway. I'll put my ability to calculate up against
anyones any day and I still consider a computer far better. I also follow my early
teachings which demand a very conservative use of the tables.
Your system prohibits 2 of the best parts of my system.
Your reasons are inadaquate (steel/wetsuit) or wrong or non-existant (console drag).
You have not adaquately supported your positions on these issues and fudged on one
(steel/setsuit), yet you simply claim to be right. Right about what? That we all
have to dive DIR?
Claim if you like that your system is safer. Safety is not my only concern.
Please don't claim it is better if your only criteria is safety. Say it is safer.
I dunno. You allowed for steel/wetsuit. It seemed reasonable. I've questioned
the drag (insignifigant) of a console and you have never said it is a safety issue.
Maybe you would decide that DIR could tolerate that. It's hard to guess, because of
the proposition that DIR defies logic and analysis. Aside from that (for a single
tank) the streamlining hograthian ideas used by DIR seem good enough.
DIR configuration may or may not be safer. It likely is just a bit safer. I've
always spent my time trying to figure out a configuration that is more effective. I
sometimes focus on safety, but usually I am trying to figure out new capabilities.
On those two points we just disagree on what primary considerations are and so
neither one of us is wrong... unless you say so.
Beyond those two points, we disagree on computer usage and I say that is both
a convenience and SAFETY issue. I will ask one last time. Can you calculate my deco
on a typical erratic sawtooth dive as well as a computer? If so, prove it? If not,
then a computer gives me increased bottom time and much less time spent doing
something other than hunting. Read my essays. I'm scrounging every moment down there.
Computers give me at least an extra tank per day at depth. California sport diving
frequently involves widely varying depths. To deny the use of a computer is to deny
the use of a safety device... unless you can calculate it... We're not talking about
60 feet for 10 minutes and then 40 feet for 30 minutes. That would be an unusual dive.
We're talking real sawtooth.
Think, a race car is not primarily designed for safety. It's designed for speed.
My dive system is not designed primarily for safety, it's designed for getting bugs.
If it is marginally less safe than a DIR system, then so be it.
Really, I guess my only other question would be how does no console, no
steel/wetsuit and no computer help you with getting bugs?
Thanx for responding, but really you have ignored my direct questions. That
is why I have gone to replying line by line. Our conversations have been so subject
to ambiguity. You already allowed for the Steel/wetsuit. Is a console too intolerable
and is that because of safety or drag? If a diver wants to take the time, can a
sawtooth profile be manually calculated near as well as a computer.. and why would I
want to?
Enjoy, seahunt
PS. I would have made one of your DIR demos, but the only one that was convenient to
me was held on my fifth anniversary... That was sorta out... and anyway, how would
you know if I had been there?
PPS. You mentioned your waterproof tables in a pouch. Where is this pouch? I got
no picture of this from DIR gear descriptions and a pouch is very desirable to me.
While I'm at it, the reason I like a pouch is mostly as a place for my scuba
tube/sausage/signal float. Since I consider that one of my most important safety
items, I am curious about what DIR says about those.... Dang, I hope I didn't
just start another fight!