The ECDIS on watch suddenly freezes/crashes while you are navigating a narrow, buoyed channel. What is your immediate priority?

A. Attempt to reboot the ECDIS immediately as the first action, before doing anything else about the vessel's navigation

B. Immediately revert to the vessel's designated back-up means of navigation (second ECDIS or paper charts) to maintain safe navigation through the channel without interruption, using visual/radar fixing against the charted buoys in the meantime, then address restoring the primary ECDIS once the vessel's immediate safety is assured; inform the Master promptly

C. Continue holding the current course and speed on autopilot until the ECDIS restarts on its own

D. Slow to full stop mid-channel and wait for the fault to resolve before proceeding

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