: Actually for a conventional shaped skeg, I really doubt that the
: shape matters, the angle of attack is always pretty tiny. For a
: skeg with a very short chord it might matter, might not, short
: chord wings stall much easier. Testing is in order.

: Drag also might not matter, speeds are pretty slow, a foil shape
: has more frontal area than a flat plate and frontal area
: matters. Again testing is in order.

: For a rudder a foil shape is definately better, but you're dealing
: with higher angles of attack and usually much shorter chord
: foils.

: Bill H.

Hi Bill,
A flat plate is less stable than a foil with any variations of flow. At least in the narrow chord that we'd use. A pie-shaped drop skeg is less effected with it's longer fore and aft chord.
The foil shape 'corrects' better as the pressure differential change is smoother.

A fatter front end doesn't cause drag even at low speeds, otherwise whale would have to swim backwards. :) Looking at fish shapes, slower swimming ones are fatter about 1/3 from the nose, fast swimmers at about 1/2 way back.

It's more fun to build a foil blade for a skeg than a flat blade one.
Mike Savage
South West Cork