Talador,

  Are you planning to race, cross oceans, or both?

        - Mike

 

Bjorn - "Are you sure the wing has a trim tab?"

The trim tab is on the stabilizer that is trailing the wing.

Bjorn - "A sail doesn't necessarily have a bad lift coefficient. It might even be better than a two element wingsail, depending on the shape that can be made with the sail."

A wing coefficient of lift without a flap can be 1.5. A sail has a hard time exceeding .8 typically around .6.  A Wing with a flap can have a lift coefficient around 3 (but the drag goes up.)  Lift/drag ratios of sails are around 30 to 1, where a wing can be around 140 - 1.   With a flap the wing drops down to the 30-1 range similar to the sail.

A wing can be around 4 -5 times more efficient than a wing sail depending on how perfectly the sail is trimmed. If the sail is poorly trimmed who knows? ^^

 

Bjorn - "The wingsail doesn't drag very much unless it's far from optimum trim."

The wingsails lift can equal the lift of a wing, if properly trimmed but it will always have higher drag because of the form.  I have seen some wingsails though that have the same shape and camber as a wing, so they are probably equivalent. 

I need to emphasize, it is the wings lack of drag that is its advantage, not total lift.  If the boat is heavy and draggy, a lot of inefficient sail area is better than a wing.

Talador