Navigation General · Aids to Navigation — Bridge Marking
On U.S. waters, the center of the preferred navigable channel under a fixed bridge span is typically marked at night by:
- AA red flashing light
- BGreen lights on the bridge
- CThree white lights in a vertical line on the span✓ Correct
- DNo lights at all
Explanation
Bridge lighting regulations mark the main/preferred channel span; the channel center over a fixed bridge is commonly shown with vertical white lights, with red lights marking pier/protection points. Mariners verify the specific scheme on the chart and in the Light List.
Authority: 33 CFR Part 118 (bridge lighting)
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