Which line would you consult to identify lines of equal water depth on a map?

Which line would you consult to identify lines of equal water depth on a map?

• A. Depth curve.
• B. Underwater contour.
• C. Isobar.
• D. Tide line.

Answer: (A)

Think of lines on a depth map as the contours you’d see on a topographic map, but for the bottom of a lake or sea. These lines connect points that share the same depth, so you can read off how deep different areas are just by following the line labels. The term you’d look for is a depth curve, which is the standard label for lines of equal depth on bathymetric maps. The other options don’t fit as well: an isobar maps atmospheric pressure, a tide line tracks water level at a specific tide, and while an underwater contour could describe the same idea, depth curve is the conventional and most precise term for equal-depth lines.