Definition
A single reduced sounding matching a charted contour is a position line, weak on a gently shelving bottom but strong along a steep shelf edge or a narrow channel. A more powerful technique records a series of soundings against distance run, plots them to chart scale on a strip of paper or tracing overlay, and slides that profile along the intended track until the pattern matches. Corrections for height of tide and transducer offset must be applied first.
Want to apply this on the water?
Ask Saily out loud for an example, a scenario or a simpler explanation.
Talk to Saily