Many keelboats have polar diagrams, e.g.
http://www.c34.org/faq-pages/images/polarDiag.gifHere's a description of how they are sometimes used.
http://www.sailnet.com/collections/articles/index.cfm?articleid=leonar0021Has anyone ever seen, or generated, "polar diagrams" for beach catamarans?
Mostly they are used on large keelboats as a guide for whether the crew is properly trimming the sails for the given wind speed, in order to maximize "VMG".
But what got me thinking about this was the recent thread on reaching vs W-L race courses.
If we had polar diagrams for a couple different beach cats, could we use them to define the real difference between a W-L course vs a course with a triangle shape? e.g. is a reaching leg a real "penalty" for a particular design?
Does a spinnaker cat get really get an advantage on a W-L course compared to a sloop-rigged or unirig cat?
Also, in another thread, there was some excellent data collection, using GPS and downloading digital maps, and such, that showed effects of wave angle on port vs starboard tack.
Perhaps, we are at the point where the instrumentation is compact enough, and sophisticated enough, we could actually develop polar diagrams from the data collection.
Does it even make sense to have a polar diagram for a beach cat, or do we have too many variables relative to its performance - (e.g. crew weight & position), compared to a large keelboat?
What about larger offshore multihulls, do they use polars? Farrier Trimarans? Stilettos?
