You are plotting a running fix in an area...

You are plotting a running fix in an area...

Question 1 of 2707066636ee928f7522a1c519e58

You are plotting a running fix in an area where there is a determinable current. How should this current be treated in determining the position?

Question 1 of 27070

Q

You are plotting a running fix in an area where there is a determinable current. How should this current be treated in determining the position?

🔍 Key Concepts

• Running fix (R-fix) theory: how and why you advance an earlier line of position (LOP) to a later time • Difference between dead reckoning (DR) track and track made good (TMG) when current is present • How set and drift of current affect the advancement of an LOP between two bearings taken at different times

💭 Think About

• Ask yourself: between the first and second bearing times, did the vessel actually follow its DR track, or was its motion over the ground changed by current? • Think about what you are really advancing: are you advancing the ship’s intended course and speed, or the actual motion over the ground between the two bearings? • Which choice uses the vessel’s true movement over the ground between observations, rather than just changing one bearing or just changing speed?

✅ Before You Answer

• Be clear on the definition of course and speed made good (over the ground) versus ordered course and speed through the water • Check which option correctly uses the vessel’s actual movement between the two bearing times to advance the first LOP • Eliminate any option that suggests ignoring current or treating current as a simple speed change without considering its effect on the ground track