Question 53 GLI04 - Mate of LT 500-1600 GRT

The Correct Answer is B **Explanation for B (Weather adjustment):** When a gyro-pilot (autopilot) is engaged for steering a vessel, the system aims to keep the ship on a precise course. However, external forces like waves, swell, and wind (collectively referred to as "weather" or "sea conditions") constantly attempt to push the ship off course. To maintain the accuracy and efficiency of the steering: * **Function:** The "Weather adjustment" (or "Weather control") is a sensitivity setting on the gyro-pilot that determines how large an error in heading the autopilot will tolerate before initiating a corrective rudder movement. * **Compensation:** * In **calm seas**, a high sensitivity (low weather adjustment setting) can be used, as the ship needs minimal rudder action. * In **rough seas** (varying sea conditions), the setting is increased (lowered sensitivity). This prevents the autopilot from constantly moving the rudder in response to every minor movement caused by waves (a phenomenon called "hunting"), which wastes power and slows the vessel. By increasing the weather adjustment, the pilot only applies rudder when the deviation is significant and sustained. **Explanation for other options:** * **A) Sea control:** This is not a standard or specific control term used on marine autopilots for adjusting steering sensitivity to external forces. The specific function is handled by the "Weather" or "Sea" adjustment knob. * **C) Rudder control:** While the rudder physically performs the steering action, "Rudder control" is a general term often referring to the system that physically moves the rudder (e.g., the steering gear) or the rate at which the rudder moves (the Rudder Limit or Yaw Limit setting). It is not the primary control used to compensate for *varying sea conditions* dynamically; the Weather adjustment dictates *when* and *how much* the rudder control is activated due to weather. * **D) Lost motion adjustment:** Lost motion refers to the mechanical play or slack in the steering gear system. The "Lost motion adjustment" (if present, often called Rudder or Yaw Deadband/Dead Zone) is set to ignore minor deviations that are too small to necessitate an actual rudder movement. While related to sensitivity, it is typically a fixed calibration setting focused on mechanical limitations, not the primary, variable control used by the operator to compensate for changes in wind and wave strength (the "varying sea conditions").