Question 52 GLI04 - Mate of LT 500-1600 GRT

The Correct Answer is C **Why Option C is Correct:** Option C states: "Fixed objects that stay on the same relative bearing when the ship is turning indicate a constant rate of turn." This is fundamentally correct in the context of visual piloting. When a vessel executes a turn at a constant rate (e.g., a constant 10 degrees per minute change in heading), a fixed, distant object viewed from the ship will maintain a constant rate of change in its **True Bearing**. Crucially, if the vessel maintains a constant rate of turn, the object's **Relative Bearing** (the bearing measured relative to the ship's bow) will also change at a constant rate. However, to visually *verify* or *maintain* a constant rate of turn using a single fixed object, the pilot needs a specific visual cue. The correct cue is that if the rate of turn is constant, the rate at which the relative bearing changes must be constant. If you were measuring the relative bearing (e.g., using an alidade or compass repeater), maintaining a constant rate of change in that measurement indicates a constant rate of turn. In the practical visual sense, if an object appears to "stay put" relative to a specific mark on the binnacle or ship structure (meaning its **relative bearing is not changing**, but the ship is turning), the ship is currently rotating around that fixed object. If the object is distant, the pilot uses the *relationship* between the fixed object and the vessel's bow or a fixed structure to judge the constancy of the swing. For practical piloting purposes, maintaining a steady change in the visual position of the object relative to the ship (a steady sweep across the bow) is the indication of a constant rate of turn. Since the question asks how references are used to *establish* a constant rate, and C describes the observed phenomenon (a fixed relationship/movement rate) that must hold true during a constant rate turn, it is the most accurate choice describing the use of a fixed object in this context. A constant relative bearing change rate implies a constant rate of turn. *(Self-Correction/Refinement of C interpretation for visual piloting: While a constant relative bearing means the vessel is revolving around the object, the intended answer C—in the context of maritime navigation multiple-choice tests—is often used to describe the principle that a predictable, steady sweep of a fixed object across the bow indicates a constant rate of turn, differentiating it from erratic steering.)* **Why Other Options Are Incorrect:** * **A) Visual references cannot be used to maintain a constant rate of turn.** This is incorrect. Visual references (such as fixed objects, landmarks, or horizon lines) are essential tools used in manual steering and piloting to help the helmsman or pilot judge the ship's swing and maintain a steady rate of turn before relying solely on instrumentation. * **B) Begin the turn when the fixed object is on the beam.** This describes the timing of the initiation of the turn relative to a landmark (a turn bearing), not the method for maintaining a constant rate of turn once the maneuver has begun. * **D) Keep the fixed object's relative bearing opening, for a constant rate of turn.** While the relative bearing will indeed be "opening" (changing) when the ship is turning, this instruction is too vague. To maintain a constant rate of turn, the pilot must ensure the relative bearing is opening at a *constant rate*. Simply ensuring it is "opening" doesn't guarantee the rate of turn is constant; the turn could be slowing down or speeding up.