3.
Definitions and Terminology
True Wind Direction:
The instantaneous magnetic bearing of the true wind.
Mean Wind Direction:
The average true wind direction during the race.
Tacking Angle:
The angle through which the boat turns when changing from one tack
to the next (
≈
90
7
).
4.
Introduction
4.1. Racing and wind shifts
Like most things in sailing, the wind
does not remain constant in either
strength or direction. The crew tend
to react naturally to gusts but find
wind shifts more difficult to detect.
The wind does, however, tend to
shift in regular patterns, oscillating
between a back and a veer.
These oscillations give the sailor a
chance to gain an advantage by
sailing a shorter distance to the
upwind mark.
In the diagram, the boat on the right
sails a shorter course by tacking
when headed and thereby sailing
mostly in lifts.
3
Mean wind direction
Wind
veers
Wind
veers
Wind
backs
Wind
backs
Wind
backs
Wind
backs
Wind
veers
Micro Compass U/Guide MASTER 8/2/01 11:59 am Page 4
