Yourbestsailvideo
Delay and Rounding
22 January 2026 · 5 min · 1K views
What this video covers
Two fundamental navigation concepts — bearing (demora) and relative bearing (marcación) — are defined and related through a single formula: magnetic bearing equals magnetic heading plus relative bearing.▶ 1:54 Marcación is the angle to an observed object measured from the boat's centerline (crujía).▶ 0:44 Demora is the same angle measured from magnetic north.▶ 1:14 The two are linked by the boat's heading.▶ 1:50 A key regional note: Spanish and European usage reverses the terminology used in Argentina, where the two terms swap meanings.▶ 2:40 The practical application covered is collision-course detection.▶ 2:39 If either measurement stays constant while another vessel approaches, a collision course exists.▶ 3:28 For recreational boats, demora is the more reliable check: heading on a small boat shifts constantly with wave action, which causes marcación to fluctuate even when the geometry hasn't changed.▶ 3:23 Demora, referenced to north rather than the centerline, is unaffected by those heading oscillations.▶ 4:32 The instrument used to take this measurement is the compás de demora (bearing compass).▶ 3:54 The instructor notes that the bearing compass has additional navigation uses covered in his offshore navigation courses.▶ 5:03
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