[C320-list] Knot meter

[Warren Updike]

On the older models, like our #62, the speed transducer does not have a flap that slows the inflow of water when pulling the transducer. The newer ones with the flap are a smaller diameter and would require replacing the thru-hull as well. 
Here on the Chesapeake, where water temps in the summer easily exceed 80 deg., and critters quickly take up residence in the recess of the transducer. The process of pulling the transducer is too much of a headache, so we have compromised by not using it at all. 
Research has informed me that for purposes of calculating true wind, use of SOG may produce a more accurate result than STW. Some newer devices (plotters, etc.) allow a selection of either for true wind. For those still living with Sea Talk, there is a device, about $100, that will take the SOG message from Sea Talk and inject the speed as STW in Sea Talk lingo so that the wind instrument will provide a True Wind without the paddle wheel transducer. I can't say if this device works with later versions of Sea Talk. Being that I am too old, too frugal, don't race (pick one, or all) I have decided that life is good enough without STW and True Wind. If anyone is interested, contact me and I will dig out the specifics on this device.

Warren and Pattie Updike
1994 C320 "Warr de Mar" #62

-----Original Message-----
From: Elizabeth Schwartz [mailto:schwartz781 at optonline.net] 
Sent: Friday, May 01, 2015 7:49 AM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Knot meter

Ahoy....The paddle wheel is as Don says......the devise is easily 
 removable, ..I think there is a flap that prevents water from gushing 
in when removing or placing the paddle wheel. I normally don't use the 
speedometer for day sailing, keeping the wheel clean for cruising. There 
is a plastic screw cap to hold the unit, or plug in place. Joe n 
Beth....#245     


On Fri, May 01, 2015 at 05:57 AM, Don Dixon wrote:

> There is a plug that allows the paddle wheel to be removed and 
> cleaned.  I suspect that is one of the lens things you describe (the 
> other is the depth finder).   Look in the bilge just aft of the 
> forward berth and see if paddle wheel is sitting there.  If so, swap 
> it out with the plug (thus can be done in water, just a bit messy.
>
> Regards,
>
> Don Dixon
> Stargazer, #605
> Key West, FL
>
> Sent from my iPad
>
>> On Apr 30, 2015, at 22:37, Denny Browne  wrote:
>>
>> I feel dumb. Knot meter hasn't worked since the last bottom job. I 
>> thought the yard guys bent the little paddle wheel with the sling, 
>> but I just hauled it again and there isn't a little paddle wheel. 
>> There's just this little round lens in the middle of the through 
>> hull, flush with it. Same for the depth sounder, which seems to work 
>> fine.
>> Anyone want to venture a guess as to why the knot meter might just 
>> quit? How does the gizmo in the hull know how fast you're moving 
>> through the water?
>>
>> Any insights, no matter how obvious, are appreciated.
>> Denny Browne
>> A Cappella #935
>> Redondo Beach
>>
>> Sent from iPhone, sorry for typos, grammar, etc...
>