Question 1

Navigating blind, your GPS, echo sounder and EP disagree. You…

Accepted Answer

Treat the disagreement as the information: slow down or stop and resolve it — Each source fails differently; agreement is confidence, disagreement is a warning. Following a safe depth contour meanwhile keeps you on a charted line while you think.

Question 2

Before trusting plotter positions on a paper chart, you should check…

Accepted Answer

That both use the same horizontal datum (e.g. WGS84) — A datum mismatch can shift a plotted position by hundreds of metres. Modern charts and GPS are WGS84, but older charts carry correction notes.

Navigating blind

This lesson is part of a paid course