Course to Steer Calculator

Direction of Current-CMG

 
Course to Steer Calculator
               
1.  Enter the Speed in knots of the current
 

2.  Enter the speed in knots of the boat in
relationship to the water as determined
by the boat's knotmeter: 

3:  Enter the of the direction of current
(angle CM) to the Course to Make Good (Destination being 0 degrees -
Origin is 180 deg)



  
 

course to steer

Where CM > =  90 degrees.
( Sailing With the Current )
The Power Vector Must Be => X

P = 180 - CM
CM1 = 180 - ( 90 + Power )
x = sine ( CM ) *  Current
CM2 = arc cosine ( x / Power )
CM = CM1 + CM2

Course to Steer (CS) =
180 - ( CM2 + 90)

Speed Advanced =
(p*sine(CS2)) + (c*sine(CS1))
  

couse-make-good-2     
Where CM <  90 degrees.
( Sailing Into the Current )
The Power Vector Must Be >
Current Vector

x = sine ( CM ) *  Current

Course to Steer (CS) =
arc sine ( x / Power )

CM = arc cosine ( x / Power )
CM1 = arc cosine ( x / Current )

Speed Advanced = 
(sine(CM)*p)-(sine(CM1)*c)