Seems like we had this thread earlier this Summer, with the multi-fin
advocates (me included)
spewing our religous zeal with virtue and vigor and single finners spewing
their religion as well.
(For the record, I do ride singles fins also).
We have to define the conditions to compare single vs. multi-fin speed.
Because, as Mike suggests, anyone who has used a properly designed multi-fin in
rough , water knows they give you "tiger paws" gripping and control. If you are
in control you can go very fast.
Most likely , fastest.
I remember talking to Richard Sperling ,who was a fixture on the speed circuit,
telling me how he won a speed event on his son's wave board, because of control
issues. It was very windy.
I think directional control is also very important.
And are we talking fast on a wave top to bottom, or fast on flat water?
Onshore winds or side-off?
Does not a multi-hull boat own the World speed record for sailcraft?
I am not aware that this "rabbit" has been run by the board/fin design players
to it's completion.
Planing (wetted) surface area , fin area and sail area are all huge factors.
I recall records being set on asymmetrical sails and very specialized boards
and fins.
I have played around with asymmetry on my fin designs....60/40, 70/30, 80/20
90/10 and have settled back to 50/50 because of end user confusion as to which
side pointed outwards.
Some of the fastest surfboards I have ever owned were Bonzer 5 fins by the
Campbell Bros.
Problem was , they were to "tracky" with the keel fins and the deep concaves
created too much lift up the face of waves.
I know that by pumping my quad fin short surfboard , I can go faster than a guy
standing on a longboard single fin.
We can lose the airplane analogies, because once a motor/engine is involved all
comparisons go to hell.
Even though I have a scientific background, I prefer to do my lab work on the
water.
Touchy, feely empirically derived data is more pertinent to sailing......where
the *** meets the road vs. theoretical aerodynamics.
I have seen too many theories crumble and not hold water lately, because of
false assumptions.
With sailboard fins, I think we are talking about lateral resistance vs. upward
lift. There are many parameters to consider and compare in fin and board design
before final conclusions are drawn.
Based on my experience, sounds like a lot of trial and error still needs to be
done in this area.
WARDOG
http://SportToday.org/
Quote:
> I wonder how true that is in very rough water, where once again control and
> tracking become big issues, particularly under less-than-expert sailors.
> Mike \m/
> To reply directly, remove the SpamDam.
> > My gut
> > feeling is that multi-fins are only useful in turning oriented sailing;
> > they'll never be faster than single fins.
by