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Hi Guys'
My two cents - I bought a pair of Twin Jets I know I know....Sucker ! =
and they are great for recreational diving with a single tank, open =
water, no restrictions ie. not on a wreck. I find I can move around =
using any kick style without to much trouble.

But

As soon as you put on a twin set they become a nightmare. You can't get =
enough pressure against the fin blade to safetly right your self if your =
upside down, let alone minuver easily ie. heli turns. These would be a =
complete clusterfuck in a wreck, where you need a stiff blade to =
counterbalence movement. I'm selling mine in favour of Jet fins - why oh =
why did I not just listen to you guys in the first place !!!

By the way - finally got rid of my Dacor Rig and had my first dive in =
the weekend using a backplate/harness - absolutly loved it - can't get =
over the difference !!
Cheers
Chaz

=20
  ----- Original Message -----=20
  From: Don Burke=20
  To: Jim Holcomb ; Techdiver=20
  Sent: Monday, August 06, 2001 7:04 AM
  Subject: Re: Split fins=20


  Hi, Jim,

  That's the kind of report I've been looking for.

  The split is designed to reduce the energy wasted pushing water up and =
down
  with a flutter kick.

  The frog kick is more like a oar pushing on the water, so your results =
were
  inevitable.

  Based on what David reports on using them in the Northwest, it seems =
that
  the floppy split fins have a fairly narrow "power curve" and would =
need to
  be matched to a particular rig and diver.  If the entanglement issue =
can be
  resolved, a center vented fin with replaceable battens like the Wenoka
  Reeflex might work out in some applications.

  Jim, I hate to cut you out of a commission, but since I already have =
more
  fins than shoes, I'll have to take a pass on your kind offer.  :)

  Don

  ----- Original Message -----
  From: Jim Holcomb <jimholcomb@x-*.co*>
  To: Techdiver <Techdiver@aquanaut.com>
  Sent: 05 August, 2001 21:47
  Subject: Re: Split fins


  > Split fins were made for people with a high air consumption rate =
diving on
  > shallow reefs.  I tested a couple pairs of those things when they =
first
  came
  > out.  They allow for less work (meaning less air consumption) =
traveling
  > around in a non-current type environment.  From a technical =
standpoint
  they
  > are useless.  Most cave/wreck divers use the frog kick. When I =
attempted
  to
  > use the frog kick with them I went absolutely nowhere (must be the =
physics
  > of the design?)  With a standard open water flutter or modified =
flutter
  you
  > DO move with less effort but not as far - so is that less effort or =
not?
  > But at twice the price I would be glad to sell you a pair <big =
grin>. Call
  > me at the store. <another big grin>.
  > Jim

  > From: "Don Burke" <donburke56@ne*.ne*>
  >
  > > From: Joe Citelli <joe@po*.co*>
  > >
  > > > How could a fin with less surface area and rigidity possibly =
generate
  > more
  > > > thrust in the water than a fin with greater surface area and =
rigidity?
  > >
  > > If the smaller fin puts less water in the wrong direction, less =
surface
  > area
  > > is needed.
  > >
  > > If the flex in a fin causes more water to go straight back, the =
flex is
  a
  > > good thing.
  > >
  > > An extension of your argument is the use of a 4 by 8 sheet of =
plywood on
  > > each foot.  Since that doesn't seem to work very well, perhaps the
  > > hydrodynamic problem is a bit more involved than just surface area =
and
  > > rigidity.
  > >
  > > > People like them because they are easy to kick with.
  > >
  > > Perhaps
  > >
  > > >  But you travel less distance.
  > >
  > > That isn't how I interpret the test results I have seen.
  > >
  > > >  Personally, I'd rather kick hard once to cover a given distance
  > > > than kick easy three times.
  > >
  > > I doubt the ratio is that high.  In any case, isn't the figure of =
merit
  > gas
  > > consumption for distance traveled?
  > >
  > > > The manufacturers simply had nothing to sell so they made this =
up.
  > >
  > > Perhaps, although the test results do look encouraging.
  > >
  > > >  Funny how people that buy this kind of stuff typically keep =
going
  back
  > to
  > > the
  > > > stuff in their garage that works.
  > >
  > > I'm watching all of this.  They have my attention.  Perhaps one =
day
  > they'll
  > > get my money.
  > >
  > > The entanglement issue needs to be addressed.  I touch my line =
with a
  fin
  > at
  > > least once a dive and don't need anything else to wrap the line =
around.
  > >
  > > I saw a fin with vents down the center in one of the magazines and
  perhaps
  > > that is the wave of the future.
  > >
  > > The best performers seem to have the blade bent downward in a sort =
of
  > > "ballerina set."  It would not surprise me to find that much =
improvement
  > > comes from that.
  > >
  > > Don Burke
  > > Chesapeake, Virginia

  ----------------------------------------------------
  NetZero Platinum
  Sign Up Today - Only $9.95 per month!
  http://my.netzero.net/s/signup?r=3Dplatinum&refcd=3DPT97
  --
  Send mail for the `techdiver' mailing list to =
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content=3D"text/html; charset=3Dwindows-1252" =
http-equiv=3DContent-Type>
<META content=3D"MSHTML 5.00.2314.1000" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial>Hi Guys'</FONT></DIV>
<DIV><FONT face=3DArial>My two cents - I bought a pair of Twin Jets I =
know I=20
know....Sucker ! and they are great for recreational diving with a =
single tank,=20
open water, no restrictions ie. not on a wreck. I find I can move around =
using=20
any kick style without to much trouble.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=3DArial>But</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=3DArial>As soon as you put on a twin set they become=20
a nightmare. You can't get enough pressure against the fin blade to =
safetly=20
right your self if your upside down, let alone minuver easily ie. heli =
turns.=20
These would be a complete clusterfuck in a wreck, where you need a =
stiff=20
blade to counterbalence movement. I'm selling mine in favour of Jet fins =
- why=20
oh why did I not just listen to you guys in the first place =
!!!</FONT></DIV>
<DIV><FONT face=3DArial></FONT> </DIV>
<DIV><FONT face=3DArial>By the way - finally got rid of my Dacor Rig and =
had my=20
first dive in the weekend using a backplate/harness - absolutly loved it =
- can't=20
get over the difference !!</FONT></DIV>
<DIV><FONT face=3DArial>Cheers</FONT></DIV>
<DIV><FONT face=3DArial>Chaz</FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: =
0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">
  <DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
  <DIV=20
  style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
  <A href=3D"mailto:donburke56@ne*.ne*" =
title=3Ddonburke56@ne*.ne*>Don=20
  Burke</A> </DIV>
  <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A=20
  href=3D"mailto:jimholcomb@x-*.co*" =
title=3Djimholcomb@x-*.co*>Jim=20
  Holcomb</A> ; <A href=3D"mailto:Techdiver@aquanaut.com"=20
  title=3DTechdiver@aquanaut.com>Techdiver</A> </DIV>
  <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Monday, August 06, 2001
=
7:04=20
  AM</DIV>
  <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: Split fins
</DIV>
  <DIV><BR></DIV>Hi, Jim,<BR><BR>That's the kind of report I've
been =
looking=20
  for.<BR><BR>The split is designed to reduce the energy wasted pushing =
water up=20
  and down<BR>with a flutter kick.<BR><BR>The frog kick is more like a
=
oar=20
  pushing on the water, so your results
were<BR>inevitable.<BR><BR>Based =
on what=20
  David reports on using them in the Northwest, it seems that<BR>the =
floppy=20
  split fins have a fairly narrow "power curve" and would need to<BR>be =
matched=20
  to a particular rig and diver.  If the entanglement issue can=20
  be<BR>resolved, a center vented fin with replaceable battens like the=20
  Wenoka<BR>Reeflex might work out in some applications.<BR><BR>Jim, I
=
hate to=20
  cut you out of a commission, but since I already have more<BR>fins =
than shoes,=20
  I'll have to take a pass on your kind offer.  =
:)<BR><BR>Don<BR><BR>-----=20
  Original Message -----<BR>From: Jim Holcomb <<A=20
  =
href=3D"mailto:jimholcomb@x-*.co*">jimholcomb@x-divers.com</A>><B=
R>To:=20
  Techdiver <<A=20
  =
href=3D"mailto:Techdiver@aquanaut.com">Techdiver@aquanaut.com</A>><BR>=
Sent:=20
  05 August, 2001 21:47<BR>Subject: Re: Split fins<BR><BR><BR>>
Split =
fins=20
  were made for people with a high air consumption rate diving =
on<BR>>=20
  shallow reefs.  I tested a couple pairs of those things when they =

  first<BR>came<BR>> out.  They allow for less work (meaning =
less air=20
  consumption) traveling<BR>> around in a non-current type =
environment. =20
  From a technical standpoint<BR>they<BR>> are useless.  Most =
cave/wreck=20
  divers use the frog kick. When I attempted<BR>to<BR>> use the frog =
kick=20
  with them I went absolutely nowhere (must be the physics<BR>> of =
the=20
  design?)  With a standard open water flutter or modified=20
  flutter<BR>you<BR>> DO move with less effort but not as far - so is =
that=20
  less effort or not?<BR>> But at twice the price I would be glad to =
sell you=20
  a pair <big grin>. Call<BR>> me at the store. <another big =

  grin>.<BR>> Jim<BR><BR>> From: "Don Burke" <<A=20
  =
href=3D"mailto:donburke56@ne*.ne*">donburke56@netzero.net</A>><BR>=
><BR>>=20
  > From: Joe Citelli <<A=20
  =
href=3D"mailto:joe@po*.co*">joe@polarbearinc.com</A>><BR>>=
=20
  ><BR>> > > How could a fin with less surface area and =
rigidity=20
  possibly generate<BR>> more<BR>> > > thrust in the water =
than a=20
  fin with greater surface area and rigidity?<BR>> ><BR>> > =
If the=20
  smaller fin puts less water in the wrong direction, less =
surface<BR>>=20
  area<BR>> > is needed.<BR>> ><BR>> > If the flex
in =
a fin=20
  causes more water to go straight back, the flex is<BR>a<BR>> > =
good=20
  thing.<BR>> ><BR>> > An extension of your argument is the =
use of a=20
  4 by 8 sheet of plywood on<BR>> > each foot.  Since that =
doesn't=20
  seem to work very well, perhaps the<BR>> > hydrodynamic problem =
is a bit=20
  more involved than just surface area and<BR>> > =
rigidity.<BR>>=20
  ><BR>> > > People like them because they are easy to kick=20
  with.<BR>> ><BR>> > Perhaps<BR>> ><BR>> >
=
> =20
  But you travel less distance.<BR>> ><BR>> > That isn't how =
I=20
  interpret the test results I have seen.<BR>> ><BR>> > =
> =20
  Personally, I'd rather kick hard once to cover a given =
distance<BR>> >=20
  > than kick easy three times.<BR>> ><BR>> > I doubt the =
ratio=20
  is that high.  In any case, isn't the figure of merit<BR>> =
gas<BR>>=20
  > consumption for distance traveled?<BR>> ><BR>> > > =
The=20
  manufacturers simply had nothing to sell so they made this up.<BR>> =

  ><BR>> > Perhaps, although the test results do look=20
  encouraging.<BR>> ><BR>> > >  Funny how people =
that buy=20
  this kind of stuff typically keep going<BR>back<BR>> to<BR>> =
>=20
  the<BR>> > > stuff in their garage that works.<BR>> =
><BR>>=20
  > I'm watching all of this.  They have my attention.  =
Perhaps one=20
  day<BR>> they'll<BR>> > get my money.<BR>>
><BR>> =
> The=20
  entanglement issue needs to be addressed.  I touch my line with=20
  a<BR>fin<BR>> at<BR>> > least once a dive and don't need =
anything=20
  else to wrap the line around.<BR>> ><BR>> > I saw a fin =
with vents=20
  down the center in one of the magazines and<BR>perhaps<BR>> > =
that is=20
  the wave of the future.<BR>> ><BR>> > The best performers =
seem to=20
  have the blade bent downward in a sort of<BR>> > "ballerina =
set." =20
  It would not surprise me to find that much improvement<BR>> > =
comes from=20
  that.<BR>> ><BR>> > Don Burke<BR>> > Chesapeake,=20
  =
Virginia<BR><BR>----------------------------------------------------<BR
>N=
etZero=20
  Platinum<BR>Sign Up Today - Only $9.95 per month!<BR><A=20
  =
href=3D"http://my.netzero.net/s/signup?r=3Dplatinum&refcd=3DPT97">htt=
p://my.netzero.net/s/signup?r=3Dplatinum&refcd=3DPT97</A><BR>--<BR>
Se=
nd=20
  mail for the `techdiver' mailing list to `<A=20
  =
href=3D"mailto:techdiver@aquanaut.com'">techdiver@aquanaut.com'</A>.<BR>S=
end=20
  subscribe/unsubscribe requests to `<A=20
  =
href=3D"mailto:techdiver-request@aquanaut.com'">techdiver-request@aquanau=
t.com'</A>.<BR></BLOCKQUOTE></BODY></HTML>

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