In running navigation practice, the maximum duration of a running fix should not exceed how many minutes?

In running navigation practice, the maximum duration of a running fix should not exceed how many minutes?

• A. 10 minutes
• B. 30 minutes
• C. 60 minutes
• D. 45 minutes

Answer: (B)

Running fixes are used to keep your position current between more formal fixes by projecting from a known position using your speed and course, and then updating when new lines of position are obtained. The accuracy of that projection deteriorates with time because you don’t know exactly how your speed, course, currents, or winds change in the interim. Keeping a running fix for no more than 30 minutes limits the potential drift to a manageable amount, so the plotted position remains reliable until you can re-fix with fresh observations. Shorter intervals would still work but aren’t necessary for the maximum limit, while longer intervals would allow drift to accumulate too much to trust the position.

Running fixes are used to keep your position current between more formal fixes by projecting from a known position using your speed and course, and then updating when new lines of position are obtained. The accuracy of that projection deteriorates with time because you don’t know exactly how your speed, course, currents, or winds change in the interim. Keeping a running fix for no more than 30 minutes limits the potential drift to a manageable amount, so the plotted position remains reliable until you can re-fix with fresh observations. Shorter intervals would still work but aren’t necessary for the maximum limit, while longer intervals would allow drift to accumulate too much to trust the position.