During passage planning on ECDIS, what does 'route checking' actually do, and what are its limitations that the OOW must still account for?

A. Route checking guarantees a completely safe route with no further verification needed by the OOW

B. Route checking automatically compares the planned route against the safety contour/depth and other configured parameters, flagging potential hazards along the track — but it is limited by the accuracy/completeness of the underlying ENC data, the correctness of the safety settings the OOW themselves configured, and the fact it typically only checks the track line itself, not the full width the vessel will actually occupy accounting for cross-track error, so it does not replace a proper visual/manual review of the plan

C. Route checking only functions when the ECDIS is in 'true motion' display mode

D. Route checking applies only to routes longer than 50nm

A. The tidal height at the time of transit to confirm sufficient under-keel clearance

B. The yacht's fuel consumption for that leg

C. The colour of the seabed shown on the chart

D. Only the distance to the next waypoint

A. Switch the ECDIS to standby mode and navigate by GPS position alone

B. Ignore it — ECDIS alarms are frequently false and can be left running

C. Assess the situation against the planned route and charted depths, take action to maintain safe water, and inform the Master if there is any doubt

D. Acknowledge and silence the alarm immediately so it does not distract the helmsman