A halfwinder is the predecessor of the gennaker and is used only on classic sailboats. The halfwinder is a bulbous genoa which is only attached to the bow by its neck. The halfwinder is especially useful when sailing close to the wind. There is no boom and is therefore ideal for sailing with a small crew.


Halfwinders can be built in many ways. Flat cut or not, with or without leeches. Or a luff that can be set in such a way that the sail behaves like a genoa.

Advantages of a half-winder

  • No tree is involved
  • Ideal for high wind sailing