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
------------------------------------------------------------------------
*From: *"Jeffrey Nelson via CnC-List" <cnc-list@cnc-list.com>
*To: *"cnc-list" <cnc-list@cnc-list.com>
*Cc: *"Jeffrey Nelson" <jhnelso...@gmail.com>
*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:
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
------------------------------------------------------------------------
*From: *"Bill Coleman" <colt...@verizon.net>
*To: *"RANDY" <randy.staff...@comcast.net>
*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
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--
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!
