
Chapter 3: Operation |
CDI/BDI Data
The Course Deviation Indicator (CDI) / Bearing Deviation Indicator (BDI) display comprises two data pages, selected alternately by the CDI and BDI soft keys. These pages are shown in Figure
Figure
CDI Data
The CDI display shows Cross Track Error (XTE) and Distance to Waypoint presented in a ‘runway’ format as shown in Figure
355°T | XTE |
0.05nm
WPT BRG
300°T
WPT RNG
23.2nm
TTG
STEER STARBOARD
WPT 004
04h:12m
ROUTE GOTO CDI BDI
Figure 3-13: CDI Display
The ‘runway’ represents a 0.3nm width with the vessel symbol shown at the bottom. Individual text boxes show Cross Track Error (XTE), Bearing to Waypoint, Distance to Waypoint and Time to Go (TTG). TTG is calculated on the basis of distance to destination and Velocity Made Good (VMG) towards destination.
At waypoint ranges greater than 4nm, the symbol remains at the top of the screen. As the waypoint range falls below 4nm, the symbol moves down the centre line.
The checkered pattern moves down the screen to simulate movement when SOG is greater than 2 knots (0.5knots if
BDI Data
The BDI graphical display shows deviation from the Bearing to Waypoint and Distance to Waypoint as shown in Figure