The compass knows that going right may be a header on port tack, but going right is a
lift on starboard tack. When this happens, the word "
LIFT
" will show up on the dis-
play.
During the race, as you sail upwind, you do not need to press the buttons again until
you feel your averages have changed. In other words, you don't need to push a button
every time you tack. The compass just assumes that if your port tack average is 040°
and your starboard average is 310° and you are now heading 050°, you must be on
port tack. It looks at your averages and assumes that you are on whatever tack has an
average closest to your present heading. This system works fine until you get a 45+°
permanent windshift. When this happens, it is time to start pushing buttons to reset
your port and starboard tack averages.
The upper analog portion of the display is in-tended to show you visually both how
far and in which direction your boat has turned since punching in the averages. If you
are continually seeing more and more segments on the left side of the display, you may
decide that you are into a persistent left shift pattern. Similarly, if the number of seg-
ments seem to be about the same on lifts and headers, then you might conclude that it
is a simple oscillating shift pattern. We just provide you with the information (the easy
part), we leave the rest up to you!
Beware the velocity shift.
Since the Sailcomp works independently of any actual wind data, you have to be care-
ful in the case of a velocity shift. This is not really a shift in the true wind direction,
but is only a shift in the apparent wind direction caused by a sudden gust or lull. The
best way to avoid being fooled by a velocity shift is to wait at least 10 seconds before
tacking on what you think is a real shift. This allows your boat to speed up or slow
down to the speed at which it should be going for the new wind. Remember that
velocity shifts are caused by significant changes in the wind velocity, so pay attention
to the amount of wind hitting you in the face! Most tactical experts would advise
waiting anyway, since tacking too soon may cause you to sail right back out of the
windshift you were intending to take advantage of.
34
RACING WITH THE SAILCOMP
Starboard Tack Average = 310°
Headed 4° to port
Lifted 9° to starboard
