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All questions
Navigation & chartwork

A blank wedge remains on the same relative bearing when the boat changes heading. Which cause should be investigated first?

Short answer

An onboard blind or shadow sector

Onboard structures can create vessel-fixed blind sectors. Cover them with other lookout evidence; never call them clear. Revisit Line of Sight and Shadow.

Sources and scope

Reviewed by Richard Moore on . This answer is scoped to international collision-avoidance and small-craft radar practice; check the current chart, publication, local rules and official operational guidance before acting afloat.

Quick check

A blank wedge remains on the same relative bearing when the boat changes heading. Which cause should be investigated first?