POLAR DIAGRAMS
Hi Fred,
These charts are theeeeee best thing since sliced bread!!! You get a circular chart(s) graphing boat speed vs apparent wind angle @optimum sail configurations (ie #1,#2, #3, spinnaker, boat-heel angle, etc.) graphed at various wind velocities.It takes all of your previous concepts of point-of-sail, sail selection,optimum boat speed and other psychotic disorders and throws them all out the window.Of course, these are calculated "theoretical" values......... but they will teach you a lot about your boat's potential..... they're truly amazing.Another interesting side-note is that they list the boats "righting moment"and stability. Basically, they calculate the degree of heel a specific boat can handle in a knockdown situation before it "turtles over".Give me a fax number and I'll send you a sample from my C&C34.You can call US Sailing for a list of boats they have on file.... I'm surethey have yours.
Steven Stoll, swstoll@msn.com
Ross,
Please see below the Performance Predictions for my boat, a C&C 34+ (to all of you 34+ owners, it's my gift to you!). US Sailing should be able to calculate the same for any boat as long as they have all of the design criteria for the boat--I'm surprised they don't have it for the 24s. They use a very sophisticated and proven computer model. What I am showing here are just the targets--you also get several pages of printouts showing a lot of nautical engineering values that takes more of a naval architect than me to understand.
With the full polars you get a graph which allows you to determine the same data as shown in these summarized predictions, but at any speed, wind velocity, etc. I bought the full package for my previous boat, a C&C 29, and did not consider it worth the price. If racing a boat with a full time tactician and navigator in a very serious vein, then maybe. It give info for calling "wallys," which is the kind of stuff I am going to leave to Melges and Connors. The summarized targets are worth it, however, in my mind. Just acquiring optimal downwind angle can be a huge plus, and there are significant differences from boat to boat.
UPWIND TARGETS| VTW | BTW | VAW | BAW | V | HEEL |
| 6 | 45.5 | 9.8 | 24.6 | 4.9 | 5 |
| 8 | 43.8 | 12.4 | 25.0 | 5.7 | 10 |
| 10 | 41.9 | 14.6 | 25.2 | 6.1 | 13 |
| 12 | 40.4 | 16.7 | 25.5 | 6.3 | 15 |
| 14 | 39.3 | 18.6 | 25.8 | 6.4 | 17 |
| 16 | 38.6 | 20.6 | 26.2 | 6.5 | 18 |
| 20 | 38.2 | 24.3 | 27.2 | 6.6 | 20 |
| VTW | BTW | VAW | BAW | V | HEEL |
| 6 | 172.6 | 2.6 | 163.8 | 3.2 | 0 |
| 8 | 172.6 | 3.6 | 164.0 | 4.2 | 0 |
| 10 | 172.6 | 4.6 | 164.3 | 5.1 | 0 |
| 12 | 172.6 | 5.7 | 164.7 | 6.0 | 0 |
| 14 | 172.9 | 6.9 | 166.4 | 6.7 | .5 |
| 16 | 173.1 | 8.4 | 167.2 | 7.2 | .5 |
| 20 | 17 | 11.4 | 168.1 | 8.0 | .9 |
Ron Underwood Spero, C&C 34+