Hi David, One of the features of the SailTimer App and Wind Instrument (http://www.sailtimerapp.com <http://www.sailtimerapp.com/>, http://sailtimerwind.com <http://sailtimerwind.com/>) that attracted me to buy them is that the app can create polar diagrams for your specific boat and specific set of sails you're flying. So you can have a polar for sailing wing-and-wing downwind, and a different polar for sailing spinnaker downwind. And each polar will be true to your boat’s displacement, propeller, bottom condition, sail quality, etc., not general to the make under unknown assumptions.
I’ve experimented with the feature, trying to create different polars for different headsails I use. To be truthful I haven’t completed the exercise - you have to sail all the angles in multiple wind speeds with each sail configuration. But I thought it was a cool feature, and it helped convince me to buy the system. Cheers, Randy Stafford S/V Grenadine C&C 30-1 #7 Ken Caryl, CO > On Jun 30, 2018, at 5:47 AM, David Knecht via CnC-List > <[email protected]> wrote: > > The polars for my boat predict an optimal downwind speed at an angle around > 145° true. Does anyone know what assumptions are made in this prediction > about spinnakers and whisker poles? I race non-spinnaker and often on > windward-leeward courses so we are often dead downwind and the whisker pole > makes a huge difference going downwind wing on wing. I am wondering if the > polars take this into account. Dave > > Aries > 1990 C&C 34+ > New London, CT > > <pastedGraphic.tiff> > > _______________________________________________ > > Thanks everyone for supporting this list with your contributions. Each and > every one is greatly appreciated. If you want to support the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray >
_______________________________________________ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
