Question 1

You're the OOW on a vessel's first-ever transit of a busy sound. What should this specifically change about how you keep the watch, compared to a route you've run many times before?

Accepted Answer

Increase scrutiny of the vessel's actual track against the planned route, and be more alert to any ECDIS limitations that may not have been fully identified during passage planning A first transit removes the safety margin that familiarity normally provides. SHK's investigation found insufficient crew knowledge of the ECDIS system's limitations and poor adherence to navigation procedures contributed to the grounding — both of which are more likely to go unnoticed on unfamiliar ground unless the watch is kept with deliberately increased scrutiny.

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.