You are running parallel to the coast and estimate that the current is against you. In plotting a running fix using bearings from the same object on the coast, the greatest safety margin from inshore dangers will result if what speed is used to determine the fix?
• Running fix and how assumed speed affects the plotted position • Effect of an adverse current (current against you) on your actual speed over ground • Why a navigator might choose a conservative estimate to stay farther offshore from dangers
• If the current is against you, is your actual speed over ground likely to be higher or lower than your engine/through‑the‑water speed? • When you advance your line of position (LOP) for a running fix, how does choosing a higher or lower speed move the final fix relative to the coast? • Which speed choice will tend to place your plotted position farther offshore than you might actually be, giving you a safety cushion from inshore hazards?
• Confirm how an adverse current changes speed over ground versus speed through the water. • Visualize or sketch how advancing the first bearing using different speeds (max, average, min) changes the location of the running fix relative to the coastline. • Check which option results in the most seaward (offshore) plotted position, providing the greatest safety margin from inshore dangers.
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