How do navigators use ocean swells when stars or sun are hidden?

How do navigators use ocean swells when stars or sun are hidden?

• A. Rely on land-based landmarks
• B. Follow migratory birds
• C. Read long-distance wave patterns to hold course when stars or sun are hidden
• D. Use magnetic cues

Answer: (C)

When celestial cues are unavailable, mariners turn to patterns in the sea itself. Ocean swells are long, regular waves created by distant storms, and they travel in a fairly consistent direction. A navigator watches how the crests line up and how the water is moving beneath the boat to infer the swell’s travel direction. That information provides a reliable reference to hold a chosen course even with stars and the sun hidden. This method leverages the sea’s own patterns as a guide, rather than relying on landmarks, birds, or magnetic cues.

When celestial cues are unavailable, mariners turn to patterns in the sea itself. Ocean swells are long, regular waves created by distant storms, and they travel in a fairly consistent direction. A navigator watches how the crests line up and how the water is moving beneath the boat to infer the swell’s travel direction. That information provides a reliable reference to hold a chosen course even with stars and the sun hidden. This method leverages the sea’s own patterns as a guide, rather than relying on landmarks, birds, or magnetic cues.