Which scale on a nautical chart is used to measure distance?

Which scale on a nautical chart is used to measure distance?

• A. Latitude scale
• B. Longitude scale
• C. Depth scale
• D. Compass rose

Answer: (A)

Distance on a nautical chart is read from the latitude scale. The latitude scale marks degrees of latitude, and each degree corresponds to a fixed distance (60 nautical miles), giving a reliable straight ruler for measuring how far apart two points are on the chart. The longitude scale, by contrast, varies with latitude because meridians converge toward the poles, so it isn’t a consistent measure of distance across the chart. The depth scale shows how deep the water is, not how far apart things are. The compass rose is used for direction and bearing, not distance.

Distance on a nautical chart is read from the latitude scale. The latitude scale marks degrees of latitude, and each degree corresponds to a fixed distance (60 nautical miles), giving a reliable straight ruler for measuring how far apart two points are on the chart. The longitude scale, by contrast, varies with latitude because meridians converge toward the poles, so it isn’t a consistent measure of distance across the chart. The depth scale shows how deep the water is, not how far apart things are. The compass rose is used for direction and bearing, not distance.