Navigation General · Tides
Spring tides occur when:
- AThe sun, moon, and Earth are in quadrature (90° alignment)
- BThe moon is at perigee regardless of its phase
- CThe tide range is less than the neap range
- DThe sun and moon are in syzygy (aligned, at new or full moon)✓ Correct
Explanation
Spring tides occur during syzygy — when the sun, Earth, and moon are roughly aligned (new moon or full moon). The gravitational forces of the sun and moon combine, producing maximum tidal range. Neap tides occur during quadrature when the sun and moon are at 90°.
Authority: Bowditch (Pub. 9), Ch. 9
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