Blade shape

The rowing stroke simulations revealed that the blade shape influences the relative drag and lift forces - and therefore the overall force - that can be put down by the rower through the stroke. By extension, the blade propulsive efficiency (and slip) depend on the profile shape. An obvious question, then, is which blade shape is optimal?

Comparing handle force curves during the drive portion of two identical strokes, one using the Concept2 Smoothie and one using a Concept2 Fat2 we see that the Fat2 loads up quicker after the catch. Towards the release, the Smoothie has a slightly higher loading.

Looking at the path of the blade through the water, we see that the Fat2 slips less than the Smoothie (that is, overall the Fat2 moves less towards the stern of the boat). In practical terms, this means that the Fat2 has a stronger grip on the water - especially at the catch.

Finally, when we compare the instantaneous propulsive efficiency of the Fat2 and the Smoothie during the drive, we see that the Fat2 has has a higher efficiency through most of the stroke.

Taken over the whole drive the Fat2 is approximately 1% more efficient than the Smoothie . Overall, all things being the same, the Fat2 would will finish a 2k race approximately 2 seconds faster than the Smoothie.