> Well wait a sec there, while I agree with you that if your paddle blade
> isn't completely submerged you are wasting effective paddle use, I don't
> go along with barely submerging the blade always. Rougher water will cause
> a barely submerged blade to aerate and lose efficiency and propulsion
> force.

You need to be careful to get your paddle fully submerged before applying pressure to minimize ventilation, granted that a shorter shaft makes this more difficult.

> Also if a paddler has the strength to work with a longer shaft they will
> increase velocity and efficiency a bit because they are effectively using
> a higher gear. Getting back to bicycles, I use a higher gear (longer
> shaft) because I've got the leg muscles for it and am comfortable with it.
> There is of course nothing wrong with downshifting the bike or using a
> shorter shaft if that is more comfortable.

A longer shaft does make a more efficient paddle for going fast. But for regular cruising the speed you are going probably does not need that extra length. Like Mark said a faster cadence is usually more efficient for the body. Instead of applying a lot of force slowl, the body would rather apply a lower force fast. Most people would probably benefit from a lower gear, thus a shorter paddle. This is one of the big advantages of a greenland paddle, they work with the body better. They just tend to do it with inefficiency instead of improved mechanical advantage.

> Length of the paddle isn't really the factor in slip as I understand it,
> it's the blade design. And while I agree with you that wider is generally
> better, it quickly becomes more difficult on your wrists with flutter and
> twisting. A greenland style paddle is more forgiving of sloppiness then a
> wide blade paddle is.

A greenland paddle is much more likely to flutter under power. The narrower blade sheds vortices more quickly than a wider blade and they need better technique to minimize the flutter. A greenland paddle is more forgiving in sculling type strokes due to their relative thickness.