Viewing Sea Conditions - Garmin GPSMAP 640 Manual

Symbol Weather Symbol
Thunderstorms
Foggy
Windy

Viewing Sea Conditions

The Sea Conditions screen shows information about surface conditions,
including winds, wave height, wave period, and wave direction.
From the Home screen, select Weather > Sea Conditions.
Surface Winds
Surface wind vectors appear on the Sea Conditions screen using wind
barbs that indicate the direction from which the wind is blowing. A wind
barb is a circle with a tail. The line or flag attached to the tail of the wind
barb indicates the wind speed. A short line represents 5 knots, a long line
represents 10 knots, and triangle represents 50 knots.
Wind Wind Wind
Barb Speed Direction
Calm
GPSMAP 640 XM WX Satellite Weather and XM Satellite Radio Supplement
Weather
Snow (snow showers, flurries,
blizzard, blowing snow, sleet,
freezing rain, freezing drizzle)
Smoke (dusty, hazy)
Wind Wind Wind
Barb Speed Direction
20 knots
Marine Mode: Using XM WX Weather and Audio
5 knots
10 knots
15 knots
Wave Height, Wave Period, and Wave Direction
Wave heights for an area appear as variations in color. Different colors
indicate different wave heights , as shown in the legend
➊
the screen.
The wave period indicates the time (in seconds) between successive
waves. Wave period lines indicate areas that have the same wave
➌
period. Wave directions appear on the chart using red arrows
direction of each arrow pointer indicates the direction in which a wave is
moving.
➋
➊
50 knots
65 knots
on the left of
➋
. The
➍
➌
➍
5