🔍 Key Concepts

• Difference between fix, running fix, estimated position (EP), and dead reckoning (DR) in coastal navigation • Which positions depend on a previous position and which stand alone • How observations (like bearings/ranges) vs calculations (course/speed/time) are used to define a position

💭 Think About

• Ask yourself: Which of these positions can be plotted on the chart without first plotting an earlier point? • Which option is defined by simultaneous lines of position rather than advancing or projecting from somewhere else? • Which positions are constructed from a prior DR or fix, and which are obtained directly from observations or measurements?

✅ Before You Answer

• Identify which positions are based on projecting course and speed from a known point (these rely on a prior position). • Identify which position is defined as the most reliable plotted position at a given time, normally from two or more intersecting LOPs. • Make sure the option you choose does not require advancing an earlier line of position or DR track to obtain it.