This page is the starting point for developing the expected sailing performance for Botany Bay (Oyster 55/19) hopefully this data will be helpful as I work to determine if new sails or other changes will have a dramatic impact on performance. The goal is to develop polar performance curves for the boat which can be compared as the boat is adjusted in the future. Note that at this point the multiple windspeed chart HAS been updated to take into account the 8/12/2010 and 8/15/2010 data. The 10 knt only curve is also interesting

Excel Spreadsheet of Polar Data, note - Excel does not have quite the right plotting functions but it is a start, assumed 2nd order poly, binned by 1knt true wind speed

The following chart looks at 10knts of true wind and the performance of the vessel compared to the true wind angle relative to the vessel The following chart looks at 10knts of true wind and the performance of the vessel compared to the true wind angle relative to the vessel expanded verticaly The following chart looks at 10knts of true wind and the performance of the vessel comparted to the apparent wind relative to the vessel The following chart looks at True Wind at 11knts, the cart is starting to have enough data to reflect reality. Note the up kink at the 180 degree mark which is obviously not quite right, the slope of the line should be zero at the crossover between port and starboard The 12 knot polars are definitely pretty thin on date. Not even seeing the double hump associated with the minima which is generally around 100 degrees true wind, I suspect that with additional data I can get much better information

Raw Data For Polar Plot Generation

Data Collected     Boat Speed (BS)     Speed Over Ground (SOG)     Apparent Wind Speed (AWS)     Apparent Wind Angle (AWA)     True Wind Speed (TWS)     True Wind Angle (TWA)     Rudder Angle (RA)     Sail in use Data I would like to collect      Heal Angle      Backstay setting and tension      Outhaul Setting      Jib Sheet Setting      Staysail Sheet Setting      Bottom/Prop Condition

Oyster 55/19 Polar Sailing Data For July 17, 2010 Sailing from King Harbor to Isthmus, Catalina, Departed King Harbor at 0815 and motored to the R10 bouy, note that seas were very flat (2 foot swell) on the beam, long period swell. Hull and prop are clean Backstay tension was in about 2" ABOVE the black tape mark (i.e. light air tension) Oyster 55/19 Polar Sailing Data for July 23, 2010 Sailing from King Harbor to Isthmus, Catalina, Departed King Harbor at 1550 and motored to the R10 bouy (1630), note that seas were very flat (1-2 foot swell) on the beam, long period swell. Hull and prop are clean Backstay tension was in about 2" ABOVE the black tape mark (i.e. light air tension) (i.e. normal furling position) Headstay somewhat loose, good for light and ready to furl main if needed Heading 176M COG 175M Oyster 55/19 Polar Sailing Data For July 25, 2010 Sailing from Emerald Bay, Catalina, To King Harbor Departed at 1300 seas flat (2 foot swell) on the beam, long period swell. Hull and prop are clean Backstay tension was in about 2" ABOVE the black tape mark (i.e. light air tension) (i.e. normal furling position) Headstay somewhat loose, good for light and ready to furl main if needed Starting out with staysail and main, solid running backstay tension, added jib later as wind lightend away from Catalina Heading 350M COG 354M Oyster 55/19 Polar Sailing Data For August 12, 2010 Oyster 55/19 Polar Sailing Data For August 15, 2010