Question 1

Your ECDIS shows a route that appears to pass close to a charted wreck, but the chart cell in use is several editions old. What should you do before departure?

Accepted Answer

Check for chart updates/Notices to Mariners covering that area, cross-reference against the largest-scale paper or backup chart available, and amend the route if the wreck position or any new hazards are not adequately reflected ENC data, like paper charts, requires updating via Notices to Mariners. An outdated cell may not reflect newly surveyed hazards or corrections — cross-checking against other sources and updating before relying on a route is part of appraisal/planning under chart maintenance procedures.

Question 2

You're preparing a passage plan for a coastal leg in a yacht drawing 3.2m. At one point the chart shows a least depth of 3.8m at chart datum. What MUST you check before finalising this leg?

Accepted Answer

The tidal height at the time of transit to confirm sufficient under-keel clearance Charted depths are referenced to chart datum (often LAT), so you must add the predicted tidal height for your transit time to get the actual depth, then compare to your draft plus a safety margin to confirm UKC.

Question 3

During your watch the ECDIS gives a "safety contour crossing" alarm. What is the correct response?

Accepted Answer

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 A safety contour alarm indicates the vessel may be approaching water shallower than the set safety contour. It must be investigated against the route and charted information, with avoiding action taken and the Master informed as appropriate — never simply silenced.