Using Electronic Charts; Zooming In And Out - NorthStar 972 Quickstart Manual And Reference Manual

Using electronic charts

CAUTION!
Nav aids have been
converted from official
paper charts into the
electronic format on
your screen, and there-
fore aren't necessarily
as accurate as the
paper charts. In some
areas, only the most
important nav aids may
be shown.

Zooming in and out

Reference section 1 — Using the Chart Screen
28

Using electronic charts

Electronic charts contain most of the infor-
mation from the original paper charts. You
can select which categories of data are
displayed to simplify the screen. When
used with caution, electronic charts open
up a world of navigational accuracy and
simplicity.
Chart boundaries
The 972 displays the boundary line of each
chart on the screen. You can turn
Chart
these lines off if you prefer (see Choosing
vector chart details, starting on page 35).
If you move from a highly detailed chart to
a less detailed one, you may see a sudden
change in the detail shown on the screen,
just as if you had changed from one
detailed paper chart to a less detailed one.
The displayed boundary lines may help
To get a closer look at the chart area
around your vessel or around the cursor,
press the key to zoom in. To see a wider
IN
area, press to zoom out. Each press of
OUT
or approximately halves or doubles
IN OUT
the chart scale.
indicate when this change in detail is going
to happen.
Lights and buoys
The nav aids on the
Chart
a variety of standard "aids to navigation"
used on coastal and inland waterways
throughout the United States. Most of
these aids are buoys, lights, lighthouses,
and daybeacons, which typically are main-
tained by the U.S. Coast Guard. Nav aids
warn you of hidden dangers, such as
underwater hazards, and to help you safely
navigate specific waterways and channels.
On a vector chart, when you move the
cursor over a nav aid, with popups are
turned on, the 972 displays a description in
the popup rectangle near the nav aid,
along with the distance and bearing from
your vessel to the nav aid.
NOTE:
Whenever the radar overlay is turned on
and "Auto Range" is turned on, the scales of
the chart and the radar are locked together
so that the images will line up. If you change
the scale of one, the scale of the other
changes automatically.
screen represent
Northstar 972