AIS report
Position reports leave a vessel at a fixed interval and climb to a shore receiver, whose arcs answer as each one lands.
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Marinenav
15 animationsARPA target
An acquired contact's predicted vector swings off the dashed course it was first reported on and settles onto the tracked heading.
CSSPremiumChart layers
Electronic chart layers — depth contours, soundings and navaids — break out of register over the base cell and slide back onto it in turn.
CSSPremiumClosest point of approach
A target runs its track past own ship while the range line between them shortens onto the marked closest point of approach and opens out again.
CSSPremiumCompass rose
A ticked compass card swings off the ordered heading and settles back under a fixed lubber line, the error arc on the outer scale opening and closing with it.
CSSPremiumCross-track error
A vessel is set off the track centreline until the cross-track bar reaches the limit, then the correction returns it to the line and the bar closes.
CSSPremiumCrossing alteration
The give-way vessel alters to starboard off its original heading, its track drawing behind it as it passes astern of the stand-on vessel.
CSSPremiumDead reckoning
A reckoned run extends from the last fix past its hourly ticks and retraces, the circle of uncertainty at the head growing with the distance run.
CSSPremiumLateral marks
Port and starboard lateral marks flash on their own light characters either side of a channel axis whose dashes run up-channel.
CSSPremiumMagnetic variation
A magnetic index runs out from the true index on a bearing tape and the span below measures the variation, then closes again.
CSSPremiumRadar sweep
A sweep arm turns around the range rings of a radar display, painting each target blip as it reaches its bearing and letting the last ones decay behind it.
CSSPremiumSet and drift
The set and drift of the current runs out from the head of the water-track arrow and the ground track swings across to close the vector triangle.
CSSPremiumThree-bearing fix
Three bearing lines swing apart into a cocked hat over the chart and close again onto a single plotted fix.
CSSPremiumTidal window
A tide curve crosses the required-depth rule twice and the passable window between the crossings runs down as the tide dot tracks across it.
CSSPremiumWheel-over
A vessel runs the inbound leg to the wheel-over point and the turn arc carries it round the waypoint onto the next route leg.
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