B&G Deckman - Manual (Page 79)

Chapter 5: Data
5.2
saving, and the database has room for 12 hours of information.
Selecting new time plot from the data menu will display a window
which allows you to view any of the stored data as a time series plot.
Clicking on a variable in the left hand window sends it to Selected
variables. Clicking on the right window deselects. When you have
selected all the variables you wish to plot, choose OK to draw the graph.
Figure 5.1 shows an example plotting boat speed (VS) and true wind
speed (TS).
Recent data is shown on the right hand side as is customary and the
graph will move to the left as time progresses. On the right hand side the
short labels for each variable are shown, along with the present value.
The ranges of each variable are shown at the top and bottom of each plot
and can be altered by clicking on them. This brings up the numeric
keypad. The time period—shown in the bottom left—can be changed in
the same way; the new time should be entered in minutes. Click and
drag on the display to bring up a horizontal measuring line; the
corresponding numbers are shown in red beneath the short name in place
of the present value. When on starboard tack a thick black line is drawn
across the bottom of each plot.
Note. If you are plotting a circular variable such as true wind direction
or course then you can specify a lower limit at the top of the plot than at
the bottom, so that you can get a sensible plot when the data are varying
around North, e.g. you could specify 340° to 20°.
Wind Plot
This display is specifically for monitoring the history of the wind. The
graphs are plotted vertically with the most recent information at the top,
which is unusual; the advantage given by this kind of plot is that the
changes in true wind direction can be related to the yacht’s heading—
when the wind is in the right the graph is also in the right. The true wind
speed is then plotted vertically also so that you can look for correlations
between the wind direction and wind speed—does the wind tend to go to
the right in the puffs?