🔍 Key Concepts

• Fix vs estimated position vs dead reckoning position • What information a single range and bearing to a known object gives you • Difference between a running fix and an instantaneous position

💭 Think About

• Ask yourself: If I can measure both range and bearing to a buoy whose charted position I know, what does that let me mark on the chart at that moment? • Think about whether this position relies on previous DR (dead reckoning) plots, or if it comes directly from a measurement to a known point. • Consider: Does a running fix come from multiple lines of position over time, or just one observation at one time?

✅ Before You Answer

• Verify which term is used when you have at least one line of position (LOP) that directly intersects a known point on the chart at that instant. • Check which positions (DR, EP, fix) are based on assumed or projected movement vs. actual observations. • Confirm that a running fix requires at least two LOPs at different times advanced or retarded to a common time.