Raymarine T210 User Manual page 12

Maxi Display
The Maxi Display automatically calculates your VMG to windward and
the VMG-Wind page provides acceleration or trend arrows to help you
assess the impact of changes to your course and sail trim.
Wind Shift
Like most things in sailing, the wind does not remain constant in either
strength or direction.
Every shift in the wind requires the boat to alter its heading in order to
maintain a close hauled course. A shift that allows the boat to change its
heading closer to the Mean Wind Direction is called a "lift"; a shift that
forces the boat to change course away from the Mean Wind Direction is
known as a "header".
In an oscillating wind, a boat that
regularly tacks when headed will spend
more of its time sailing a lifted course and
will sail a shorter distance to the
windward mark than a boat that regularly
sails a headed course. This gives the
boat sailing in the lifts a considerable
advantage.
In the diagram, the boat on the right sails
a shorter course by tacking when headed
and thereby sailing mostly in lifts.
The system automatically calculates the mean wind direction by
averaging the true wind direction over a period of time
Sail your boat for maximum speed and use the Maxi Display to identify
the headers and lifts to help you decide when to tack or gybe.
Permanent wind shifts can be recognised as a constant header on
one tack, and a constant lift on the other tack. In this situation, you can
reset the mean wind direction as follows:
1. Go to the Wind Shift page
2. Press
Direction.
3. The new value is displayed; if required, it may be adjusted using
and
Note: resetting the mean wind direction manually disables averaging
until the system is switched off.
10
, the mean wind direction is reset to the current True Wind
.
www.tacktick.com