Diff. between wave & slalom & speed sails?

Diff. between wave & slalom & speed sails?

Post by David Ch » Sun, 14 Oct 1990 06:32:01


Since I plan to hit the waves as soon as I get my jibes down pat, I
bought a couple of used Neil Pryde CombatWave sails.  When sailing
these under flat conditions, I noticed that for the same amount of
force, they were slower than slalom sails.  So can someone please
explain the design criteria for wave vs. slalom vs. speed sails?
Also, what is the purpose of half battens for wave sails?  I suspect
that it would be a good idea to post the answers as well as reply to
me, since there are probably other people who would be interested.

        Dave

 
 
 

Diff. between wave & slalom & speed sails?

Post by Juri Munk » Sun, 14 Oct 1990 16:56:34

Quote:

>Since I plan to hit the waves as soon as I get my jibes down pat, I
>bought a couple of used Neil Pryde CombatWave sails.  When sailing
>these under flat conditions, I noticed that for the same amount of
>force, they were slower than slalom sails.  So can someone please
>explain the design criteria for wave vs. slalom vs. speed sails?
>Also, what is the purpose of half battens for wave sails?  I suspect
>that it would be a good idea to post the answers as well as reply to
>me, since there are probably other people who would be interested.

Wave sails do not need to be as fast as slalom sails. Once you are
going fast enough and there is enough wind for you to jump high,
the extra speed will not be of any real help. Wave sails have to
be easy to waterstart with and most of the sail area has to be
higher than with a slalom sail. When you are behind a large wave,
the wind can not hit the lower part of your sail.

The half battens on wave sails are there because wavesailors often
want to totatally depower their sails. You probably know how well
a cambered sail keeps powered up even you try to luff it. A RAF
sail is slightly easier to luff and a wave sail is something that
you can depower completely. Once you have no sail power, you are
essentially surfing.

I used to have a Neil Pryde RAF Speed 4.4. Speed sails are the exact
opposite of wave sails. Most of the area is below the boom, so these
sails are really hard to waterstart with. Modern speed sails have large
amounts of camber inducers and they are practically always powered up.

Personally I like wave/slalom and allround slalom sails much more than
either type of sail. My recommendation is that you should get all your
sails with basically the same cut, so that you won't even notice a
difference when sailing on a 5.6 or a 4.3. Usually people get a large
race sail (7.5 or 6.5), a medium size slalom sail (5.0,5.5 or 6.0) and
a smaller set of wave sails (4.5,4.0,3.5 or smaller). The idea is that
these are the optimum sizes for these types of sails. The problem
is that you have to learn to rig all these sails correctly even though
you might be able to use the 3.5 only once per year.

In my case, I know how much tension a 7.2 or 5.6 needs, so I can
apply most of the knowledge to rigging the 3.6 and 4.3. To be honest,
I have to admit that a 3.6 Infinity looks more like a wave sail than
a slalom sail. The 4.3 is much more like a slalom sail.

   ____________________________________________________________________________
  / Juri Munkki     /  Helsinki University of Technology   /  Wind  / Project /

 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~