I sail on a reservoir in Colorado. It has neither tides nor currents nor seas :) Except for powerboat wake, which makes the lake choppy on calm days. And the occasional wind-driven whitecapped waves when the breeze is really up.
Cheers, Randy ----- Original Message ----- From: "Jeffrey Nelson via CnC-List" <[email protected]> To: "cnc-list" <[email protected]> Cc: "Jeffrey Nelson" <[email protected]> Sent: Tuesday, September 27, 2016 5:07:55 PM Subject: Re: Stus-List C&C Polars Again Perfect. Btw, depending on where you sail, your Speed over water won't ever match. By doing the math between the two you can determine how much current you are in and with some calculations how much that is setting you off course. Food for thought. On 9/27/2016 7:46 PM, RANDY wrote: Speed over ground - the SailTimer App uses GPS to calculate speed. And it's showing about 0.75 - 1.0 knots faster than my onboard transducer-based speed instrument. Since I trust GPS more, I'm now calibrating the onboard instrument to match the speed shown by the app. I scrubbed my bottom a few weeks ago but couldn't see to get the keel (murky marina water), so I'm sure it's not perfectly clean. Cheers, Randy ----- Original Message ----- From: "Jeffrey Nelson via CnC-List" <[email protected]> To: "cnc-list" <[email protected]> Cc: "Jeffrey Nelson" <[email protected]> Sent: Tuesday, September 27, 2016 3:42:46 PM Subject: Re: Stus-List C&C Polars Again Add a dirty bottom at this time of year and they'd work for my boat too. :-) Are you using speed over ground or speed over water for your baseline speed? -- Cheers, Jeff Nelson Muir Caileag C&C 30 Armdale Y.C. Halifax On 9/27/2016 6:24 PM, RANDY via CnC-List wrote: <blockquote> Those are a reasonable approximation but they're from a 30E, the European edition of the 30, which has a different design from my MK I (e.g. reverse transom, different interior, probably different displacement), and who knows what sails and what kind of prop etc. That boat is apparently fastest on a shallow broad reach, probably under spinnaker. Assuming I can get an accurate set of polars for my boat this year, they'll still show lower speeds than the boat's true potential, because I have old tired sails including an undersized main, and I have a fixed prop. Even so I'd like to get an accurate set of polars as a baseline to compare against when I have new sails and a folding prop, hopefully next year. Then hopefully I can sail the boat to its true speed potential. Cheers, Randy ----- Original Message ----- From: "Bill Coleman" <[email protected]> To: "RANDY" <[email protected]> Sent: Tuesday, September 27, 2016 1:26:24 PM Subject: RE: Stus-List C&C Polars Again Can’t you just use the polars given on that site? They have a C&C 30 Wind velocity 6kts 8kts 10kts 12kts 14kts 16kts 20kts Beat angles 45.5° 43.7° 43.3° 43.7° 43° 41.3° 40.5° Beat VMG 2.55 3.08 3.46 3.8 4.14 4.39 4.53 52° 3.98 4.73 5.31 5.82 6.15 6.35 6.5 60° 4.26 5.02 5.65 6.08 6.34 6.52 6.72 75° 4.51 5.3 5.94 6.29 6.49 6.67 7.02 90° 4.64 5.61 6.24 6.55 6.71 6.8 7.04 110° 4.77 5.75 6.31 6.63 6.93 7.23 7.53 120° 4.65 5.63 6.24 6.57 6.86 7.18 7.75 135° 4.27 5.19 5.97 6.39 6.67 6.96 7.56 150° 3.68 4.6 5.39 6.04 6.4 6.66 7.21 Run VMG 3.19 3.99 4.69 5.33 5.92 6.31 6.83 Gybe angles 148.1° 152.1° 153.5° 159.8° 180° 180° 180° Right? Regards, Bill Coleman _______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated! </blockquote> -- Boat_Sig Cheers, Jeff Nelson Muir Caileag C&C 30 Armdale Y.C. Halifax _______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated!
_______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated!
