Asymmetric spinnaker design

[TJL]

A curiosity question - what is the difference between an asymmetric spinnaker designed for an offshore yacht compared to an asymmetric spinnaker from an 18 foot skiff?

[powerabout]

when you say offshore yacht do you mean a planing hull

[TJL]

This poses a variation on the same question - what is the difference in design between an asymmetric for an offshore planing hull versus an offshore displacement hull?

[Doug Lord]

You might be better off asking a sailmaker. Generally, the faster the boat the flatter the spinnaker .On very fast boats the asy spin becomes a screecher-very flat and more jib like-and can be roller furled.

[Stumble]

TJL,

Just to elaborate on what Doug said. The design of the sail itself doesn't really change much. What changes is the designed angle of the apparent wind to the sail while flying. An asymetrical made for sailing dead down wind will look pretty much the same regardless of the boat, it will have a large windward projection, and a deeper cut draft.

As the apparent wind angle moves forward (either due to boat speed, or sailing angle) the ideal sail will loose the windward projection, and the draft will start to flatten to look more like a jib. Typically the sails are given codes based upon their designed apparent wind angle, with a Code 0 being the most upwind, then a code 1a, code 2a, ect.

In addition the weight of the material tends to get heavier as the sail is designed more for upwind. Though code 0's are often very light, since they can replace a wind seeker in very light air.