AhaBulbStuff Everyone Should Know
AhaBulb: Stuff Everyone Should Know · ahabulb.com/boat-sternlight-only-overtaking

At night you see only another boat's white sternlight, no red or green. What situation is this?

You are overtaking it, so you keep clear.

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  1. Meeting head-on
  2. Crossing
  3. Overtaking ✔

Why: Inland Rule 13 says you're overtaking when you come up more than 22.5 degrees behind the other boat's beam, where at night you'd see only its sternlight. The overtaking boat must keep clear.

Huh, didn't know that: Rule 13 says if you're in any doubt whether you're overtaking, assume you are.

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Why did the fish get bad grades? It was below sea level.
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References

Answer: Overtaking. Inland Rule 13 says you're overtaking when you come up more than 22.5 degrees behind the other boat's beam, where at night you'd see only its sternlight. The overtaking boat must keep clear.

  1. 33 CFR 83.13 Overtaking, Inland Rule 13 (eCFR) www.ecfr.gov/current/title-33/section-83.13
    at night she would be able to see only the sternlight of that vessel but neither of her sidelights.
    Checked 2026-10-08.

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