Furuno FAR-2218-BB Operator's Manual page 153

How to set the check area around own ship (B-type only)
When [5 AZ POLYGON] is set to [AROUND CHECK AREA], the area details must be
set. To setup the check area, do the following procedure. This procedure is abbrevi-
ated, and takes into consideration that [AROUND CHECK AREA] is selected.
1. Select [6 CHECK AREA SETTING].
2. Referring to the figure below, use the number keys to enter a distance for [PORT],
[STBD], [BOW] and [STERN]. You can also spin the scrollwheel, then left-click to
enter these values.
[ PORT ] [ PORT ]
setting setting
The area shown in gray is the "check area".
The available setting range for all four values is [0.0NM] to [16.0NM]. The default
setting for all four values is [1.0NM].
[ BOW ] [ BOW ]
setting setting
[ STBD ] [ STBD ]
Own
setting setting
ship
[ STERN ] [ STERN ]
setting setting
3. TARGET TRACKING (TT)
3-23