100+ Free SAMSA Chief Mate CoC Practice Questions

Explanation: IMO Resolution A.893(21) specifies that passage planning consists of four key stages: Appraisal (gathering all relevant information), Planning (preparing the detailed voyage plan), Execution (executing the plan with appropriate briefings), and Monitoring (continuously monitoring vessel progress). Skimping on any stage compromises navigation safety and violates STCW standards. Chief Mates are responsible for supervising the berth-to-berth passage plan prepared by the navigation officer.

Explanation: The Safety Contour on an ECDIS marks the boundary between safe navigable water and unsafe shallow water. If a vessel's route crosses the safety contour or if the vessel enters shallow water inside the safety contour threshold, ECDIS generates an audible and visual anti-grounding alarm. The Chief Mate must calculate the required safety contour based on maximum static draft, squat, tide, and safety margin.

Explanation: Rule 19(d) of COLREGs governs conduct of vessels in restricted visibility when risk of collision exists. An alteration of course to port for a vessel forward of the beam (except when overtaking) must be avoided because it often worsens the close-quarters situation. Early and substantial action by altering course to starboard or reducing speed is required.

Explanation: Squat is the reduction in under-keel clearance caused by hydrodynamic pressure drops under a moving hull. The magnitude of squat increases proportionally to the square of vessel speed (V^2) and is directly proportional to the block coefficient (Cb). In confined channels (canals or shallow fairways), squat can double compared to open shallow water.

Explanation: The Marcq St. Hilaire Intercept method compares the sextant observed altitude (Ho) with a calculated altitude (Hc) from an assumed position. The difference (Intercept = Ho - Hc) along the calculated azimuth yields a precise Position Line perpendicular to the azimuth line, suitable for plotting on a navigational chart.

Explanation: Rule 10(c) requires crossing vessels to cross on a heading as nearly as practicable at right angles (90 degrees) to the general direction of traffic flow. Heading at right angles minimizes the time spent in the lane and makes the vessel's intention clear to traffic proceeding along the lane, even if wind/current causes drift.

Explanation: Raster Navigational Charts (RNC) are direct digital raster image scans of official paper charts. While visually identical to paper charts, RNCs do not contain vector data layers, meaning ECDIS cannot query individual objects or trigger intelligent depth safety alarms automatically, unlike S-57/S-101 ENCs.

Explanation: A Great Circle track represents the shortest distance between two terrestrial points on a sphere. However, because it crosses meridians at varying angles, the true heading changes continuously. A Rhumb Line crosses meridians at a constant angle (straight line on Mercator), but is longer than the Great Circle distance except along the equator or meridians.

Explanation: ARPA algorithms can suffer from target swap (exchanging target vectors when two vessels pass in close proximity) or processing lag during target maneuvers. Watchkeepers must cross-check ARPA data against visual observations and manual radar plotting technique to verify vector accuracy.

Explanation: South Africa follows IALA Maritime Buoyage System Region A. When entering port from seaward (conventional direction of buoyage), port hand marks are RED (can-shaped) and kept to port, while starboard hand marks are GREEN (conical-shaped) and kept to starboard. Memory aid: 'Red Right Returning' applies only in Region B (Americas, Japan, Philippines, Korea).