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

[Bill Lowe]

 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)