Catalina 310 Polars

rukidn

.
Apr 23, 2012
158
Catalina 310 258 Sandusky, OH
I'm playing around with weather routing (Open CPN) and wondering if anyone has polars for our boat. We aren't racers, just a learning exercise, but planning a long trip and would be interesting to play with the weather routing capabilities. Searching this forum and online, I've found nothing for the 310. Thanks, Ed
 
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rukidn

.
Apr 23, 2012
158
Catalina 310 258 Sandusky, OH
Thanks! The C30 may be closest. A good enough place to start for my purposes. Planning a 10 and 12 hour sails next weekend; a good time to measure vs. reality. BUT wind forecast is light and right in our face.
 

rukidn

.
Apr 23, 2012
158
Catalina 310 258 Sandusky, OH
Over the winter I researched Polar programs and found the 20 year old PCSAIL Excel program developed by David Martin at the U of Michigan. It's hard to find the source file online but I did find and download the student version, which only ran on obsolete Excel 2000. I can't find the full non-student version, which is likely not public domain. I've been able to modify and get it running on Excel 2010 with the Solver add-in, and it should work on newer but I haven't had time to test it. I have to say the Excel code and the math nearly made my Engineer head explode. This is Masters or PHD thesis stuff. I made no change to the calculations, so I assume the results are per the original program. I did add Polar plotting capability on an additional tab.

Our 310 is fin keel with the 150 genoa. There are quite a few parameters to enter for the hull and sails. I had to assume some of the dimensions until I was able to get to the boat and measure, but I found that correcting my assumptions didn't make too much difference to the end results. I played with a lot of the parameters and for the most part results were in the same ballpark. I was a bit concerned that the results did exceed theoretical hull speed by a bit. So I do wonder what "student version" means.

The plot for our boat with main and jib is attached. I don't know if appropriate to post the Excel file here, but you can PM me if you want to play with it. This was a good winter obsession, but now we just want to get in the water and sail. Fair winds. /Ed

PS: It snowed 6" today...
 

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