7
WIND 3150 Installation and Operation Manual
NAVMAN
Apparent wind speed and angle are the values
measured by the masthead unit on the boat. True
wind speed and angle are calculated values that
allow for the relative speed of the boat.
If the boat is moving, then the apparent wind speed
is different to the true wind speed and the apparent
wind angle is different to the true wind angle, as
shown below.
If the WIND 3150 is not connected to a speed
instrument, then the unit always displays apparent
3 Display apparent or true wind speed and angle
Boat moving upwind. Apparent wind speed is greater than true wind speed and apparent wind angle is
closer to dead ahead than true wind angle:
Boat is
at rest
Wind, 20 kts
from North
True
wind
speed
20 kts
Boat moving downwind. Apparent wind speed is less than true wind speed and apparent wind angle is
closer to dead ahead than true wind angle:
True
wind
speed
20 kts
True
wind
speed
20 kts
Boat speed
10 kts
True
wind
speed
20 kts
Boat speed
10 kts
Boat speed
10 kts
Apparent
wind speed
15 kts
Boat speed
10 kts
Apparent
wind speed
15 kts
True wind
angle
45°
True wind
angle
135°
Apparent
wind
angle
107°
Apparent
wind
angle
30°
Apparent
wind speed
28 kts
Apparent
wind speed
28 kts
Boat is at rest. Apparent wind speed equals true wind speed and apparent wind angle equals true wind
angle:
wind speed and angle. If the WIND 3150 is connected
to a boat speed instrument, press
to display
apparent or true wind speed and angle:
Press
Apparent values
True values
