On a clear afternoon in open water, the only person aboard a charter boat engages the autopilot and goes below for ten minutes to make lunch. Which rule has been broken?
- Rule 6, because a speed held by autopilot is never a safe speed
- Rule 8, because no action to avoid collision was being taken
- No rule, because traffic was light and the visibility was good
- Rule 5, because a proper lookout must be kept at all times
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D. Rule 5, because a proper lookout must be kept at all times
Rule 5 has no exception for good weather, light traffic or autopilot: someone must be looking and listening the whole time the vessel is underway. Light traffic affects what a safe speed is, but it does not excuse leaving the vessel with no lookout.
Reference: Navigation Rules (International and Inland, 33 CFR 83), Rule 5
Under Rule 6, a safe speed is one that allows a vessel to do what?
- Stay under the posted harbour limit while still keeping enough way on to steer properly
- Stop within exactly half the distance of the visibility in every condition
- Take proper and effective action to avoid collision and stop in a suitable distance
- Reach her destination on schedule without making an excessive wake
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C. Take proper and effective action to avoid collision and stop in a suitable distance
Rule 6 defines safe speed by its result: the vessel can take proper and effective avoiding action and be stopped within a distance appropriate to the circumstances. Stopping in half the visibility is a useful rule of thumb in fog, but it is not the definition in the rule.
Reference: Navigation Rules (International and Inland, 33 CFR 83), Rule 6
The compass bearing of a tug with a long tow is changing noticeably as you approach it at close range. What does Rule 7 say about risk of collision here?
- Risk cannot exist once the bearing is changing appreciably
- Risk exists only if the tug sounds the danger signal
- Risk is judged only by the bearing of the tug itself, not that of her tow
- Risk may still exist when approaching a tow or a very large vessel
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D. Risk may still exist when approaching a tow or a very large vessel
Rule 7 warns that risk may exist even with an appreciable bearing change, particularly with a very large vessel, a tow, or any vessel at close range, because different parts of it lie on different bearings. A changing bearing on the tug says nothing about clearing the barge astern of it.
Reference: Navigation Rules (International and Inland, 33 CFR 83), Rule 7(d)(ii)