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Safe Speed and Narrow Channels Quiz: 10 Real USCG Exam Questions

Rules 4 to 10 are the ones that never switch off. Day or night, clear or foggy, you keep a look-out, hold a safe speed, watch for risk of collision, act early, and stay where you belong in channels and traffic lanes. Here are 10 questions on those rules, pulled word for word from the USCG Rules of the Road question bank. Answer each one in your head, then tap "Show answer" to check yourself and see the rule behind it.

Every question here applies under both International and Inland rules, and none need a diagram. Explanations are checked against the rule text in the U.S. Coast Guard Navigation Center (NAVCEN) Navigation Rules handbook. Where Inland differs, like the Western Rivers downbound rule in Inland Rule 9(a)(ii), the Rule 9 page spells it out.

The quiz

Question 1. BOTH INTERNATIONAL & INLAND A proper look-out shall be maintained __________.

  1. only at night
  2. only during restricted visibility
  3. at night and during restricted visibility
  4. at all times
Show answer

D. at all times

Every vessel shall at all times keep a proper look-out by sight and hearing, plus all available means that fit the conditions, such as radar. Daylight, clear weather, and an empty horizon don't change that. See Rule 5.

Question 2. BOTH INTERNATIONAL & INLAND Every vessel should at all times proceed at a "safe speed". "Safe speed" is defined as that speed where __________.

  1. you can stop within your visibility range
  2. you can take proper and effective action to avoid collision
  3. you are traveling slower than surrounding vessels
  4. no wake comes from your vessel
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B. you can take proper and effective action to avoid collision

Safe speed is a speed that lets you take proper and effective action to avoid collision and be stopped within a distance appropriate to the prevailing circumstances and conditions. Stopping within your visibility range sounds sensible, but it isn't the definition, and the Rules set no fixed number of knots. See Rule 6.

Question 3. BOTH INTERNATIONAL & INLAND In determining "safe speed", all of the following must be taken into account EXCEPT the __________.

  1. maximum horsepower of your vessel
  2. presence of background lights at night
  3. draft of your vessel
  4. maneuverability of your vessel
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A. maximum horsepower of your vessel

Rule 6(a) lists the factors every vessel must weigh, including maneuverability (6(a)(iii)), background lights at night (6(a)(iv)), and draft in relation to the available depth of water (6(a)(vi)). Maximum horsepower is not on the list. See Rule 6.

Question 4. BOTH INTERNATIONAL & INLAND The Rules state that risk of collision shall be deemed to exist __________.

  1. whenever two vessels approach from opposite directions
  2. if the bearing of an approaching vessel does not appreciably change
  3. whenever a vessel crosses ahead of the intended track of another vessel
  4. if one vessel approaches another so as to be overtaking
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B. if the bearing of an approaching vessel does not appreciably change

Risk of collision shall be deemed to exist if the compass bearing of an approaching vessel does not appreciably change. See Rule 7(d)(i). Keep Rule 7(d)(ii) in mind too: risk can still exist with a bearing change, especially when approaching a very large vessel, a tow, or a vessel at close range.

Question 5. BOTH INTERNATIONAL & INLAND Which procedure(s) shall be used to determine risk of collision?

  1. Watching the compass bearing of an approaching vessel
  2. Systematic observation of objects detected by radar
  3. Long-range radar scanning
  4. All of the above
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D. All of the above

All three come straight from Rule 7. Watching the compass bearing of an approaching vessel is Rule 7(d). If your radar is fitted and working, Rule 7(b) calls for proper use of it, including long-range scanning for early warning and radar plotting or equivalent systematic observation of detected objects. See Rule 7.

Question 6. BOTH INTERNATIONAL & INLAND What is a requirement for any action taken to avoid collision?

  1. When in sight of another vessel, any action taken must be accompanied by sound signals.
  2. The action taken must include changing the speed of the vessel.
  3. The action must be positive and made in ample time.
  4. All of the above
Show answer

C. The action must be positive and made in ample time.

Any action taken to avoid collision shall, if the circumstances of the case admit, be positive, made in ample time, and with due regard to good seamanship. Rule 8 doesn't require a speed change or sound signals with every action. A change of course alone can be the right move. See Rule 8(a).

Question 7. BOTH INTERNATIONAL & INLAND A vessel proceeding along a narrow channel shall __________.

  1. avoid crossing the channel at right angles
  2. not overtake any vessels within the channel
  3. keep as near as safe and practicable to the limit of the channel on her starboard side
  4. when nearing a bend in the channel, sound a long blast of the whistle
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C. keep as near as safe and practicable to the limit of the channel on her starboard side

A vessel proceeding along a narrow channel or fairway keeps as near to the outer limit on her starboard side as is safe and practicable. See Rule 9(a). Overtaking in a channel isn't banned. Rule 9(e) covers how to do it.

Question 8. BOTH INTERNATIONAL & INLAND Which vessel shall NOT impede the passage of a vessel which can safely navigate only within a narrow channel or fairway?

  1. A vessel of less than 20 meters in length
  2. A vessel sailing
  3. A vessel fishing
  4. All of the above
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D. All of the above

All three. A vessel of less than 20 meters and a sailing vessel shall not impede the passage of a vessel that can safely navigate only within a narrow channel or fairway (Rule 9(b)). A vessel engaged in fishing shall not impede the passage of any other vessel navigating within the channel (Rule 9(c)). See Rule 9.

Question 9. BOTH INTERNATIONAL & INLAND In a traffic separation scheme, when joining a traffic lane from the side, a vessel shall do so __________.

  1. at as small an angle as possible
  2. as nearly as practical at right angles to the general direction of traffic flow
  3. only in case of an emergency or to engage in fishing within the zone
  4. never
Show answer

A. at as small an angle as possible

Vessels normally join or leave a traffic lane at the end of the lane. When joining or leaving from either side, they do it at as small an angle to the general direction of traffic flow as practicable. See Rule 10(b)(iii). Don't mix this up with crossing: Rule 10(c) says to cross on a heading as nearly as practicable at right angles to the traffic flow.

Question 10. BOTH INTERNATIONAL & INLAND A vessel using a traffic separation scheme shall NOT __________.

  1. cross a traffic lane
  2. engage in fishing the separation zone
  3. proceed in an inappropriate traffic lane
  4. enter the separation zone
Show answer

C. proceed in an inappropriate traffic lane

A vessel using a traffic separation scheme shall proceed in the appropriate traffic lane in the general direction of traffic flow for that lane (Rule 10(b)(i)). Crossing a lane is allowed when you have to (Rule 10(c)), and a vessel may enter a separation zone to cross the scheme, in an emergency, or to fish within the zone (Rule 10(e)). See Rule 10.

How did you do?

If you got 9 or 10, you know the rules that apply in any visibility. If you missed a few, read the rule pages for safe speed, risk of collision, narrow channels, and traffic separation schemes. Then try the COLREGS practice test for a mixed set. Want another topic? Take the right of way quiz, the navigation lights quiz, or the sound signals quiz.

Want the rest of the Rules 4 to 10 questions? Practice all 1,272 USCG questions, with missed-question review, in COLREGS: Rules of the Road for iPhone and iPad. Download on the App Store

Prefer the browser? The free web study tool has all 1,272 questions.

Frequently asked questions

Are these real USCG exam questions?

Yes. All 10 come word for word from the USCG Rules of the Road question bank, the same 1,272 questions used in COLREGS Prep.

How many questions on Rules 4 to 10 are in the question bank?

In COLREGS Prep, 70 questions are tagged to Rules 5 to 10: 23 to Rule 9, 16 to Rule 7, 14 to Rule 10, 10 to Rule 6, 5 to Rule 8, and 2 to Rule 5. Six of the Rule 9 questions are Inland only or International only. None are tagged to Rule 4 itself, which simply says these rules apply in any condition of visibility. A rule tag is a rough guide, since lights and sound signal questions often test these rules too.

What is a safe speed under the Rules of the Road?

Rule 6 defines safe speed as a speed that lets you take proper and effective action to avoid collision and be stopped within a distance appropriate to the prevailing circumstances and conditions. There is no fixed number. You weigh factors like visibility, traffic density, maneuverability, background lights at night, wind, sea and current, and your draft against the available depth.

Do Rules 4 to 10 apply in fog and at night?

Yes. Rule 4 says the rules in this section, look-out, safe speed, risk of collision, action to avoid collision, narrow channels, and traffic separation schemes, apply in any condition of visibility. In restricted visibility, Rule 19 adds its own duties on top of them.

Does a sailboat have the right of way in a narrow channel?

No. Under Rule 9(b), a sailing vessel shall not impede the passage of a vessel that can safely navigate only within a narrow channel or fairway. Rule 10(j) says the same for a sailing vessel near a power-driven vessel following a traffic lane.

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