Off-Scale Channel Indicator (XTD Indicator)

The indicator is designed to monitor the ship’s position relative to the route axis and the cross-track distance (XTD) limits on the current route leg.

Hint

The indicator is only available when a route is activated.

The XTD boundaries displayed on the indicator may be symmetric or asymmetric, depending on the route settings.

№	Element	Description
1	Current route leg axis	Route centerline
2	Left XTD boundary	Left minimum allowable deviation boundary
3	Right XTD boundary	Right minimum allowable deviation boundary
4	Distance to axis	Distance from the own ship to the route axis
5	Scale	In current units of measurement
6	Ship	Off-scale ship symbol. Symbol rotation indicates the ship’s direction of movement relative to the current route leg axis
6	Red band	Band occupied by the ship in the track lane. Red — the ship has partially or fully exceeded the XTD limits
7	Green band	Band occupied by the ship in the track lane. Green — the ship is fully within the XTD limits

Important

Calculation of the band occupied by the ship is only performed when heading data is available. In the absence of a heading sensor, the off-scale ship symbol is always displayed vertically.

With a significant deviation from the route, to facilitate return to the route, the indicator will always display the route axis, XTD band, and ship symbol.

№	Element	Description
1	Route	Track lane
2	Ship	Off-scale ship symbol. Symbol rotation indicates the ship’s direction of movement relative to the current route leg axis

Caution

The indicator calculates the ship’s position on the current route leg. If a different WP is selected in the Routes window, the indication of the ship’s position on the route leg may not correspond to reality.

This situation may occur with a significant deviation from the route and subsequent return to it.

Exercise particular caution when interpreting the Channel indicator readings.