Asymmetric spinnakers When sailing a fast boat like a multihull there is no question about the advantages of a gennaker compared to a traditional spinnaker. Not only does the gennaker give an improvement in performance, it is also much more easy to handle. A gennaker is an asymmetric spinnaker, not just in the sense that the luff is longer than the leech - that is just to make it possible to fly it without a spinnakerpole. The big difference is the asymmetric cross section of a gennaker, with a round entry, the maximum beam forward of the midpoint and a flatter exit. This is of course a superior shape when the apparent wind is always more or less on the beam. The gennaker will direct the power forward instead of sideways - into speed instead of heeling.