🔍 Key Concepts

• Chart symbols for positions such as fix, dead reckoning (DR), running fix, and estimated position (EP) • Difference between a precise position and a predicted or approximated position • Standard plotting symbols used in traditional coastal navigation

💭 Think About

• Think about which of these positions is usually completely enclosed (for example, by a circle) versus one that is partially enclosed, like with a semi-circle. • Ask yourself: which type of position depends on measured lines of position (LOPs) and which depends mainly on course and speed through the water? • Consider which type of position symbol is used when you are least certain of your exact location and are allowing for possible error.

✅ Before You Answer

• Verify which symbol on a standard paper chart uses a full circle versus a semi-circle. • Check which position type (fix, DR, running fix, or EP) is associated with no visual or electronic observations, only course, speed, and time. • Confirm from a navigation textbook or plotting guide which position symbol is used when allowing for current, wind, and other unknowns.