> I launched my boat the day before yesterday, I noticed that the paddle
> tends to vibrate a little on each stroke, it's not quite a flutter, but
> there is definatley a vibration there. What would cause this? . Is this
> normal with greenland sticks?

Any paddle can have a tendancy to flutter although european blades with the blade set somewhat behind the center of the shaft do it less.

The fluttering is caused by vortex sheading occurring on alternating edges of the blade. The solution to this is like Jay said, angle the bottom edge of the paddle slightly forward. This forces the vortex to occur on just that side eliminating the flutter. As you start the release of the stroke, angle the bottom edge of the blade slightly towards the stern. This motion is pretty natural and if you are not already doing it, you will quickly adapt to it. People who don't experience the flutter are probably doing this already.