Ternav 4

What information is absolutely necessary to plot a starting point for dead reckoning?

• The direction of wind and current in the area.

• The type and size of your vessel

• A known position obtained from GPS, celestial navigation, or landmark identification

• The speed and course you intend to maintain throughout the journey.

The passage mentions using a compass rose to plot the course line. What is the primary function of the compass rose in this context?

• To calibrate the accuracy of your compass.

• To measure the distance traveled along the course line

• To translate degrees of your desired course direction into a line on the chart

• The compass rose is not required for plotting a DR position.

According to the passage, why is it recommended to use a different colored pen for plotting the DR course line on the chart?

• A specific color signifies the direction of travel.

• Colored ink dries faster on nautical charts.

• Using the same color for the DR line helps to blend it in with the chart.

• It helps to distinguish the DR line from the charted information for better readability.

The steps for plotting a DR position involve calculating a distance based on speed and elapsed time. What unit is typically used for speed in dead reckoning calculations?

• Knots

• Degrees

• Meters per second

• Kilometers per hour

The passage advises noting down any course corrections made during the journey. How can this information be helpful when plotting a DR position?

• By indicating course changes with dashed lines, you can create a more accurate picture of the vessel's path.

• It allows for recalculating the speed based on the altered course

• Course corrections won't affect the final estimated DR position.

• Noting course corrections is only necessary for long journeys.

What is the main difference between a straight position line and a circular position line in navigation?

• A straight line requires a compass rose, while a circular line doesn't.

• Straight lines are more complex to plot compared to circles.

• A straight line position line indicates a possible location based on direction (course or bearing), while a circle represents possible locations based on a measured distance.

• Straight lines are used for celestial navigation, while circles are for landmarks.

The passage describes three types of position lines. Under which scenario would a navigator likely use a hyperbolic position line?

• When plotting a dead reckoning position for a short journey.

• When determining the ship's location based on the measured altitude of a celestial body.

• When taking a bearing of a familiar landmark sighted visually.

• A hyperbolic position line is not a common method in modern navigation

According to the passage, what information is essential for plotting a circular position line around a fixed point on the chart?

• The direction of travel (course) of the vessel.

• The speed of the vessel and the elapsed time since the last fix.

• The measured distance between the vessel's current location and the fixed point.

• A circular position line cannot be plotted without the ship's course information.

The passage mentions using a compass rose when plotting a straight position line from a landmark bearing. What is the role of the compass rose in this step?

• To measure the distance between the vessel and the landmark.

• The compass rose is not necessary for plotting a position line from a bearing

• To check the accuracy of the ship's compass against the charted compass rose

• To convert the measured bearing of the landmark into a line direction on the chart.

The passage states that plotting a hyperbolic position line is a complex process. Why is this type of position line considered more challenging compared to others?

• It requires a special tool not commonly found on board vessels

• It involves extensive calculations using complex mathematical formulas.

• Hyperbolic lines require reference data from a nautical almanac and additional calculations for interpretation

• A hyperbolic position line represents a larger area of uncertainty compared to other lines.