Ok that made me laugh :D 

That's why I first noticed that speed via the replay. I sure as hell am not 
looking at my iPhone in the middle of that kind of chaos :) In fact this past 
Wednesday night when I finally got a rail in the water, I even forgot to look 
at my clinometer in all the excitement - but I suspect she was heeling around 
30 degrees. I know 25 degrees isn't enough to get the rail wet. 

Cheers, 
Randy 

----- Original Message -----

From: "Gary Nylander via CnC-List" <cnc-list@cnc-list.com> 
To: "cnc-list" <cnc-list@cnc-list.com> 
Cc: "Gary Nylander" <gnylan...@atlanticbb.net> 
Sent: Friday, May 19, 2017 12:11:53 PM 
Subject: Re: Stus-List Fun Race Last Night 



I remember that Randy is on a lake in Colorado. More than likely his burst of 
speed is the hull settling into the water as it goes faster and thus increasing 
the waterline ā€“ and/or being heeled over which also increases the waterline. 
When my 30-1 gets the rail in the water in 20-30 knots of wind, I am generally 
too busy to look at the speed. 



Iā€™m sure all of you nautical types remember the war stories about clipper ships 
going so fast they literally bury themselves as the make a bigger and bigger 
hole in the water. I am not interested in trying that. 



Oh well. 

Gary 



From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Gary Russell 
via CnC-List 
Sent: Friday, May 19, 2017 2:01 PM 
To: C&C List <cnc-list@cnc-list.com> 
Cc: Gary Russell <captnga...@gmail.com> 
Subject: Re: Stus-List Fun Race Last Night 




Remember your GPS gives you speed over ground, while Hull Speed is speed over 
the water. A one knot favorable current can easily explain the difference. 





Gary 


S/V Kaylarah 


'90 C&C 37+ 


East Greenwich, RI, USA 





~~~~~~~ _ / ) ~~~~~~ 





On Fri, May 19, 2017 at 1:16 PM, Ronald B. Frerker via CnC-List < 
cnc-list@cnc-list.com > wrote: 




GPS is usually in miles per hour IIRC. Knots is faster by about 15%, so 6.7kt 
times 1.15 would be about 7.7mph. 


Unless your GPS is set in kt in which case this is all wrong. 


Ron 


Wild Cheri 


C&C 30-1 


STL 












From: RANDY via CnC-List < cnc-list@cnc-list.com > 
To: cnc-list < cnc-list@cnc-list.com > 
Cc: RANDY < randy.staff...@comcast.net > 
Sent: Thursday, May 18, 2017 3:52 PM 
Subject: Re: Stus-List Fun Race Last Night 





I'm just as surprised as anyone. I know that 1.34 times the square root of 
24.75 (Grenadine's waterline in feet) is 6.67 knots. But apparently that's only 
a very general rule - see 
http://www.boats.com/reviews/crunching-numbers-hull-speed-boat-length and 
https://en.wikipedia.org/wiki/Hull_speed . At 9,000 pounds displacement I 
guarantee I'm not planing :) 





But I assume GPS doesn't lie. On June 22nd last year I was using RaceQs during 
a race. I forgot to switch it off after finishing, so it recorded Grenadine 
sailing for fun in the 25-33mph gusts that piped up after the race, under full 
main and 150% genoa (which tore that night, before I could get a rail in the 
water). If you watch this replay from 19:42:50-19:43:00 local time, you'll see 
Grenadine going 7.5 knots over ground according to RaceQs GPS-based iPhone app: 


http://raceqs.com/tv-beta/tv.htm#userId=1032518&divisionId=41508&updatedAt=2016-06-23T03:05:38Z&dt=2016-06-22T18:08:05-06:00..2016-06-22T21:05:54-06:00&boat=Grenadine
 





I'm not one to look a gift horse in the mouth :) Maybe at 25 degrees of heel my 
waterline length is appreciably longer than 24.75 feet. Or maybe I just have to 
give credit to George Cassian, George Cuthbertson, and Rob Ball for designing a 
faster-than-predicted hull form. 





Cheers, 


Randy 






From: "David Knecht via CnC-List" < cnc-list@cnc-list.com > 
To: "CnC CnC discussion list" < cnc-list@cnc-list.com > 
Cc: "David Knecht" < davidakne...@gmail.com > 
Sent: Thursday, May 18, 2017 1:25:19 PM 
Subject: Re: Stus-List Fun Race Last Night 





Theoretical hull speed of a C&C 30 is 6.7 knots (based on 25ā€™ water line). How 
are you hitting 7.6-8? Foils? Dave 









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_______________________________________________ 

This list is supported by the generous donations of our members. If you wish to 
make a contribution to offset our costs, please go to: 
https://www.paypal.me/stumurray 

All Contributions are greatly appreciated! 

_______________________________________________

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make a contribution to offset our costs, please go to:  
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All Contributions are greatly appreciated!

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