[C320-list] Speed Increase by Installing App on Smart Phone - How to calibrate knotmeter?

[Dean Vermeire]

Good info, Jeff.

I am thinking I want the knotmeter properly calibrated because I would 
expect the true/apparent wind speed and angle functionality to be more 
accurate.  True?

Thanks,
Dean Vermeire
Moonstruck II (#847)

On 8/4/2015 12:45 PM, Jeff Hare wrote:
> Hi,
>
> On a lake without current, I agree you should just calibrate it so that you
> can go faster and kick everyone's butt.  :)
>
> If you sail where there are tides and currents and have a chart
> plotter/depth/speed/wind instruments tied together, then properly calibrated
> knot meter and wind instrument can make quite a bit of difference in showing
> the strength and direction of currents you're sailing against (or with).
> Without calibrated gear you miss out on some helpful data, mostly because
> the chart plotter calculates current vectors based on GPS course/speed
> combined with knot meter speed through the water and compass heading.
>
> Specifically, you might opt to run with the current or tide now to make
> better speed over ground even if it takes you off your line, especially if
> you can plan for a reversing current to help pull you back in line later.
> In our area there are times when I need to head more into a current early
> knowing that it will increase or change direction later along my route.
> Sailing a direct line might force me to point to close to the wind to
> counter the increased tidal current and stay off the shore.  Can make the
> difference between being able to sail and having to motor.  Around here if
> you don't take advantage of the current, you're missing a lot.
>
> -Jeff
>
> -----Original Message-----
> From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf
> Of Bill Lowe
> Sent: Monday, August 3, 2015 9:49 AM
> To: C320-List at Catalina320.com
> Subject: Re: [C320-list] Speed Increase by Installing App on Smart Phone -
> How to calibrate knotmeter?
>
>   Dean,
> I have the manual and have calibrated my speed readout several times.
> Recently, I have been sailing to your marina fairly frequently to help some
> friends who recently bought "Sunlower" a hunter 28.5 there. I would be glad
> to loan you my manual if you don't have one.
>
>
> Bill
> Papillon
> #1146
>
>
> -----Original Message-----
> From: Dean Vermeire <dean at vermeire.us>
> To: Catalina 320 List <C320-List at Catalina320.com>
> Sent: Mon, Aug 3, 2015 8:00 am
> Subject: [C320-list] Speed Increase by Installing App on Smart Phone - How
> to calibrate knotmeter?
>
>   
>   
>   
> First of all, I should point out that after 40 years of sailing, our
> Catalina 320 (which we have had for 4 years) is our first boat with speed
> and wind instruments.  Electronics aren't all that necessary on a lake in
> Kansas.
>   
> So, when I see that I am doing about 2.2 knots in 6-10 knots of breeze on a
> beam reach, or motoring at 2.5 knots with the yanmar humming along at 2500
> RPM, I really don't have anything to compare to.  And then, some of you
> folks talk about motoring at 6-7 knots, so I just figure that I should
> switch out the 2-blade prop for a 3-blade.  But when you talk about sailing
> at 6-7 knots or more, and the most I have been able to get out of her is 5
> knots with the Asym flying in a good breeze, I start thinking one of two
> things - either the knotmeter is lying to me, or I suck.
>   
> Yesterday, I downloaded a simple GPS app, "SailDroid", to my phone. My
> knotmeter says 2.2 knots.  The phone says 4.5!  This is not definitive
> proof, but I'm going to say that I do not suck!
>   
> It is amazing how it feels like you are going faster, just because some
> widget thinks you are.  :)
>   
> The paddlewheel sending unit is only 2 years old.  Is there a way to
> calibrate the knotmeter (ST-60)?
>   
> Thanks,
> Dean Vermeire
> Moonstruck II (#847)
>   
>   
>
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>
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