Re: [Paddlewise] Greenland paddles - throw/swing weight

John asks some good questions; here are my answers:

John Winters wrote:

> ... If the lower style is more efficient
> (less work) why do racers paddle differently? Seems to me they would want
> to do less work. There are those who paddle very upright and find it more
> relaxing than the low style. How is this explained? 

The higher angle stroke, when done properly, *is* more efficient, and
the difference in efficiency becomes important at race speeds (or when
sprinting, for example to catch a wave).  However the difference in
efficiency is very small at the speeds at which most kayakers cruise. 
Moreover, the high-angle stroke is somewhat more difficult to master,
and if done improperly (or with an improperly sized paddle) there is a
significant reduction in efficiency gain.  With sufficiently poor
technique (or with a sufficient error in paddle sizing) the "gain" may
be negative, and the Greenland paddle may actually result in less
work.   

John also asks:
> 
> I am confused. If the Greenland paddle slips through the water more easily
> then isn't more energy lost? If so, why does it use less energy? 

It doesn't use less energy, it uses more energy, but the difference is
trivial. Proponents of Greenland paddles point out that the effect of
the slippage is to mimic the effects of using a "lower gear" in cycing,
reducing stress.  I say "mimics" because it is not quite the same--there
is no slippage when using a lower gear on a bicycle.  A more efficient
way of reducing the "gear" of your paddle is to use a shorter shaft (but
with a modern blade), in combination with a more vertical stroke.  But
again, the difference in efficiency is trivial for most folks.
  
> It seems to me that if the Greenland paddle slips
> through the water more it must have a lower drag coefficient than the
> modern style of blade. If so, why can't the modern style be made smaller
> yet so it will have the same net drag but will have a smaller blade and be
> lighter than the Greenland style?   

It could, but the cost of customizing the grip size, etc., for each
individual paddler would be prohibitive.  A very substantial advantage
of the Greenland paddle is that it is possible to make and modify such a
paddle at very low cost. One can get a paddle that is highly
customized.  The cost of producing "one-off" modern paddles is much
higher.  I'm sure that there are many folks who have a great time making
and customizing their Greenland paddles.  In the end they have something
that works quite well, even if there is some (trivial) loss in
efficiency.  Moreover, there may be some gain in ease of rolling (as you
acknowledge).  So you end up with a low-cost, highly customized paddle
that is fun to make, easy to use, nearly as efficient as a modern
paddle, and facilitates rolling.  What is it again that you don't
understand?  

> Another puzzle. The Greenland stroke is
> wide (well away from the side of the boat) as such does it not tend to
> cause more turning and thus waste energy that would be spent on propulsion
> forward?

Absolutely.  Although once again it is easy to overstate the importance
of this at low speeds.

(Disclaimer: I use a short, ultralight graphite paddle, and prefer a
vertical stroke.) 

Dan Hagen
Bellingham, Washington
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