Posted by Marc Hall on July 20, 2001 at 18:47:56:
In Reply to: And your point is?? posted by seahunt on July 19, 2001 at 21:53:13:
>You sound like a revisionist historian.
Well if you think so. I tend to try understand
the basic reasoning behind some of the
simplified statements like "Never dive steel
tanks in the ocean" and see how they apply to my
diving environment.
>Easier than what? What about swimming through >kelp paddies? Do you swim backwards with your >wings? Do they work well when swimming forward?
I find it easier to swim underwater thru the kelp
beds in a DIR setup then any other other gear
arrangement I have worn. The latest setup that
is currently sitting in storage is based on
a Scubapro Classic Jacket with standard Octopus,
Oceanic 3 gauge console and standard length hoses.
The DIR setup was designed to be clean and streamlined. It originated in caves where there
was a concern about not becoming tangled in cave
line or keyholed in some restriction. No gear is
supposed to hang below the plain of your lower
body when you are in the horizontal position. So
your not dragging gear across the bottom when you
are only inches off the bottom. (You may not dive
like this, but I do pretty frequently). The SPG
is clipped off on the left hip D-Ring and the hose
is the proper length. If it was longer the hose
would arc out away from your body and me more
likely to become entagled on something.
The short hose regulator is on a necklace around
the neck and is both hose and second stage runs
close to the body. This hose is the proper length
as well. The configuration also maintains the
long hose (primary) regulator close to body.
When not in use the primary regulator is clipped
off on the right chest D-ring so its not dangling
out in the open. When not in use the light head
is clipped off to the right chest D-ring as well
and the cord is run under the waist strap so it
is not dangling. The wings are also very conforming to body and tank and properly sized.
Since we are maintaing proper trim and buoyancy
and are not overweighted to begin with the about
of air in the wing is minimal so the
crosssectional area of diver moving thru the
water is minimized as well.
So swimming thru kelp beds there is limited
oppurtunity for gear to get entangled.
I tend to avoid swimming thru kelp beds or
paddies on the surface with good dive planning
and navigation skills. However since the DIR
gear setup is so clean and streamlined it
seems to be easier to move thru the kelp on
the surface as well. Swimming over the top of
the kelp I always swim on my stomach in any
gear configuration I have worn.
For normal surface swims I swim on back in both
the DIR and other rigs the vast majority of
the time. Even when I use to wear the old chest
mounted BCs I spent the majority of surface time
on swimming on my back. Wing type setups which
place the buoyancy underneath you while swimming on the surface on your back and seem to be more
comfortable then other buoyancy units like
Scubapro Classic Wings or chest mounted BCs.
>>There are DIR purists who believe dive computers
>>are acceptable for recreational divers.
>Careful, I agree, but there are others here that >will burn you for that statement.
Divers need to know the limitations of the algorithms that are programmed into their computer.
>>The only back tanks I own are steel(actually I
>>do have an aluminum 60something in storage). I
>dive a single steel 95 in my wetsuit although
>>I have yet to dive in my wetsuit this year.
>Again, that gets some DIR people, ON THIS BBS, >very hot. Interesting your vies on these points. >They are the main gear issues I have with a >strict DIR configuration. I'm glad you see it my >way.
But I am not sure you see it my way.
Steel tanks can be inappropriate for certain dives. The bottom line is based on proper bouyancy/weighting during the dive.
In a drysuit buoyancy during the dive is only
going to swing by the weight of the air in the
tank. At the beginning of the dive you are the
most negative due to the weight of the gas in
the tank(s). At the end of the dive you are
more buoyant since the gas has been exhausted
from the tank.
With a wetsuit you also have the buoyancy swing
of the neoprene compression. The deeper you go
the more negative you are.
You need to be properly weighted so that you can
maintain a deco stop at the end of the dive. Oh
we are talking recreational diving here so in
PADI/NAUI/SSI,etc terms we will call it a
"safety stop" (I honestly don't know the difference).
You also need to not be overweighted at the
beginning of dive. If your BC fails you need to
be able to swim to surface with your gas supply.
If you need to drop disposable weight to do this
then that is somewhat acceptable. At least you
get off the bottom althought you may not be
able to control your ascent rate as you approach
the surface.
It is quite possible that with a wetsuit and a
steel tank setup that you may not be able to
meet the second criteria even after dropping
your disposable weight. If you would wear an
Al 80 instead with more positive buoyancy
charteristics you could be wearing more
disposable weight. Other DIR alternatives might
be to wear an aluminum backplate instead of a
steel one. But it really depends on the buoyancy
charateristics of your entire rig.
>>The console is an entanglement problem. The gauges
>>are better placed on the arm.
>>You have an entanglement problem with a console.
>Nicely, I don't.
Sorry, we disagree on this and I guess I don't really believe you. Maybe you could explain
how you manage it.
I also find the data I need to be much more
readily available if the gauges are on my
wrists. I also don't have to reach for my
console when I want access to critical data.
I also like to leave my hands free for other
things and not have to occupy one with holding
the console whenever I need access to the data.
During recreational dives my hands are frequently
busy with camera and strobes and it is nice to
just be able to glance down at my wrists to see
my gauges.
>>Sounds like you chose not to shore dive in >>Florida. I have not yet either but when I lived
>>in the Bahamas I would do shore dives and some
>>pretty long swims. There is no kelp in Florida,
>>but then there is no fire coral in California.
>You can avoid fire coral, but you almost must >swim in kelp
You can avoid both if you chose not to dive in
areas were they exist. Again I don't spend
much time swimming on the surface over kelp.
Never have in any gear configuration I have worn
and I have done plenty of kelp diving. I guess
I used to do it quite a bit when I spearfished,
but I was freediving and it is pretty easy to
avoid entanglement when you are just wearing a
wetsuit and weight belt.
>I'm not surprised, but I'd still like to try >backplate and wings out.
Good. I have a spare backplate and single tank
wings that you could try on your next trip to San
Diego.
>Where are there muddy bottoms in CA? Actually, >most of my contact with the reef or kelp is when >I brachiate. It's a very controlled touch >causing very little disturbence and then I'm gone.
Mud may have not been the best term to use.
How about silty bottoms or bottoms that are
easily stirred by divers fins. Examples
would be La Jolla Shores, many of the spots in
Laguna Beach, Monterey Breakwater.
>>Every dive is a deco dive.
>Well there are dives where you calculate from >the tables and some you don't.
On every dive you will be ongassing and
offgassing gas from your body tissues and fluids.
Offgassing involves deco. I don't see much difference between coming up at a
prescribed "safe" ascent rate, doing a "safety
stop" or doing a "deco stop". Its all being done
for the same reason.
>>You are one disagreeable cuss, but that's your privilage.
I think I could say the same for you, but "cuss"
might be too close to a swear word and this
message pulled from the board :-)
Marc Hall
svcfish@yahoo.com
>You are one disagreeable cuss, but that's your privilage.
enjoy, seahunt