🔍 Key Concepts

• Dead-reckoning (DR) position vs. fix vs. estimated position (EP) • What you need to form a true fix on the chart • How a single line of position (LOP) is used when time or data is limited

💭 Think About

• Ask yourself: With only one LOP, do you know your exact position, or just a likely area along that line near your DR? • Think about how navigators label a position on the chart when it is based partly on a DR and partly on one observed LOP. • Consider what extra information (how many LOPs, separated by how much time or angle) is needed before you can call it a fix or a running fix.

✅ Before You Answer

• Verify the definition of a fix (how many LOPs and what relationship between them). • Recall what an estimated position symbol represents on a chart and what information it’s based on. • Make sure you know what a running fix requires: LOPs taken at different times and advanced/retarded to a common time.