sailboat seamanship 183
On the other hand, if both cars were traveling in the same direction and one hit
the other, neither driver would feel much impact because the diff erence in their
speeds would be negligible. Similarly, when we are running downwind (with
the true wind behind the boat), our boatspeed partially counteracts the true
wind speed, and the apparent wind is lighter than the true wind. Remember
these two facts about course changes and apparent wind:
If you change course toward the
true wind, apparent wind speed in-
creases.
If you change course away from
the true wind, apparent wind speed
decreases.
When you are closed-hauled, the apparent
wind is stronger than the true wind. When
you are running, the apparent wind is not
as strong as the true wind.True wind speed changes. In sailing, we deal with three phases of true
wind: the steady wind phase, the gust wind phase, and the lull wind phase. Gust
and lull wind phases operate like the accelerator pedal in your car. If you need
to pass another vehicle, you accelerate for a short while. If you need to slow
down to allow a vehicle to pass you, you decelerate for a short while.
In Chapter 4 we learned about the basic concept of lift s and headers. Here
we learn how lift s and headers can occur not just when wind direction changes,
but when velocity changes as well.
A wind gust accelerates above the baseline steady wind for a short period of
time. Sailors call a gust from the same direction as the baseline breeze a velocity
lift because the apparent wind moves away from the bow. If you’re sailing close-
hauled, you can point your boat closer to your windward destination during a
gust from the baseline wind direction. As your boat speeds up in response to the
stronger wind, however, the apparent wind will move forward again—though
perhaps not enough to force you all the way down to your previous baseline
close-hauled course.
A lull decelerates below the steady wind for a short period of time. Sailors
call a lull from the baseline wind direction a velocity header because the appar-
ent wind moves toward the bow. When sailing close-hauled, you will have to
respond by falling off the wind somewhat, which points you farther from the
windward destination you are trying to reach.
Th e discussion of lift s and headers in Chapter 4 suggests that you should
always tack on a header to keep moving toward your destination, but a velocity