Lop by bearing from charted object
One of the simplest and most common LOPs is developed from a single bearing on a charted object. The bearing can be taken using a pelorus (see Chapter 2), or a handbearing compass, or by orienting the boat so that the resulting relative bearing is dead ahead (000R), abeam (090R or 270R), or astern (180R). Bearings so determined could be compass bearings if the ship’s compass is used, magnetic bearings if a hand-bearing compass is used in a location where it is free of deviation, or relative bearings if a pelorus is used. If a relative bearing is taken, it must be converted to a true bearing by first determining the compass heading at the instant of the relative bearing observation, correcting this compass heading to a magnetic heading by applying deviation, and then to a true heading by allowing for variation.
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