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USCG Master 100 practice questions

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Question 1Rules of the Road

Under the Rules of the Road, which statement describes the requirement for a proper look-out?

  1. It must be kept at all times by sight and hearing and by all available means. Correct answer.
  2. It must be kept only when another vessel's lights or shapes are actually sighted.
  3. It must be kept only in restricted visibility or in congested water.
  4. It must be kept only while the vessel is making way through the water.

Explanation

Rule 5 requires every vessel to maintain a proper look-out at all times by sight and hearing as well as by all available means appropriate to the prevailing circumstances and conditions. The obligation is continuous and is not limited by visibility, traffic density, or whether the vessel is moving.

Question 2Rules of the Road

Two power-driven vessels are meeting on reciprocal courses so as to involve risk of collision. What action does each vessel take?

  1. Both alter course to port and sound two short blasts.
  2. Both stop their engines and sound five short and rapid blasts.
  3. Both hold course and reduce speed until the other passes.
  4. Both alter course to starboard and sound one short blast. Correct answer.

Explanation

In a head-on situation each vessel must alter course to starboard so that they pass port side to port side, and each signals the maneuver with one short blast. Neither vessel is a stand-on vessel in this situation.

Question 3Rules of the Road

How are the sidelights of a power-driven vessel underway arranged?

  1. Red to port and green to starboard, each over an arc of 225 degrees.
  2. Green to port and red to starboard, each over an arc of 112.5 degrees.
  3. Red to port and green to starboard, each over an arc of 112.5 degrees. Correct answer.
  4. Red to port and green to starboard, each over an arc of 45 degrees.

Explanation

A sidelight shows an unbroken light over an arc of 112.5 degrees, from right ahead to 22.5 degrees abaft the beam on its own side. Red is fitted on the port side and green on the starboard side.

Question 4Rules of the Road

Under the Inland Rules, a power-driven vessel that intends to overtake another vessel on that vessel's port side sounds:

  1. Two prolonged blasts followed by two short blasts.
  2. Three short blasts.
  3. Two short blasts. Correct answer.
  4. One short blast.

Explanation

Under the Inland Rules the overtaking signal is given in short blasts: one short blast means an intention to pass on the other vessel's starboard side and two short blasts mean an intention to pass on her port side. The vessel to be overtaken then answers with the appropriate agreement signal.

Question 5Rules of the Road

Over what arc does a masthead light show?

  1. 360 degrees, so that it is visible from any direction.
  2. 135 degrees on each bow, ending 45 degrees abaft the beam.
  3. 225 degrees, from right ahead to 22.5 degrees abaft the beam on each side. Correct answer.
  4. 112.5 degrees, from right ahead to 22.5 degrees abaft the beam on each side.

Explanation

A masthead light is an unbroken white light showing over an arc of 225 degrees, from right ahead to 22.5 degrees abaft the beam on either side. That forward-facing arc is what lets another vessel judge whether she is seeing the approach head-on or from a crossing angle.

Question 6Rules of the Road

Power-driven vessel A sees power-driven vessel B fine on A's starboard side, and risk of collision exists. Which vessel must keep out of the way?

  1. Neither vessel, because both must hold course and speed.
  2. Whichever vessel is making the greater speed through the water.
  3. Vessel A, because B is on A's starboard side. Correct answer.
  4. Vessel B, because she is on A's starboard side.

Explanation

When two power-driven vessels are crossing so as to involve risk of collision, the vessel that has the other on her own starboard side must keep out of the way. Vessel B is the stand-on vessel and must keep her course and speed.

Question 7Rules of the Road

In or near an area of restricted visibility, what signal does a power-driven vessel making way through the water sound?

  1. One prolonged blast at intervals of not more than two minutes. Correct answer.
  2. One short blast at intervals of not more than one minute.
  3. Two prolonged blasts at intervals of not more than two minutes.
  4. One prolonged blast and two short blasts at intervals of not more than two minutes.

Explanation

A power-driven vessel making way through the water sounds one prolonged blast at intervals of not more than two minutes. The same vessel, when stopped and making no way, sounds two prolonged blasts with a short interval between them.

Question 8Rules of the Road

Which of the following is a recognized distress signal under the Rules?

  1. Firing a gun at intervals of about one minute. Correct answer.
  2. Showing three all-round green lights in a vertical line.
  3. Hoisting a black ball where it can best be seen.
  4. Sounding five short and rapid blasts on the whistle.

Explanation

The distress signals listed in the Annex include a gun fired at intervals of about one minute and a continuous sounding with any fog-signalling apparatus. They are signals indicating that a vessel is in distress and requires immediate assistance.

Question 9Rules of the Road

A power-driven vessel proceeding along the course of a narrow channel or fairway shall:

  1. Anchor clear of the channel whenever another vessel approaches from ahead.
  2. Keep to whichever side of the channel has the deepest water for her draft.
  3. Keep in the middle of the channel and post an extra look-out forward.
  4. Keep as near to the outer limit on her starboard side as is safe and practicable. Correct answer.

Explanation

Rule 9 requires a vessel in a narrow channel to keep as near to the outer limit of the channel that lies on her starboard side as is safe and practicable. Keeping to the deepest water or the centerline defeats the purpose of a common traffic pattern.

Question 10Rules of the Road

A power-driven vessel is approaching a bend in a narrow channel where other vessels may be hidden by an intervening obstruction. What signal does she sound?

  1. One prolonged blast. Correct answer.
  2. Five short and rapid blasts.
  3. One short blast followed by one prolonged blast.
  4. Two prolonged blasts.

Explanation

A vessel nearing a bend or an area of a channel where other vessels may be obscured sounds one prolonged blast. Any approaching vessel that hears it answers with one prolonged blast.

Question 11Rules of the Road

At night, a vessel restricted in her ability to maneuver displays three all-round lights in a vertical line. What is the arrangement?

  1. White at the top, red in the middle, white at the bottom.
  2. Red at the top, red in the middle, red at the bottom.
  3. Green at the top, white in the middle, green at the bottom.
  4. Red at the top, white in the middle, red at the bottom. Correct answer.

Explanation

The three all-round lights shown by a vessel restricted in her ability to maneuver have red as the highest and lowest and white in the middle. By day the same vessel shows a ball over a diamond over a ball.

Question 12Rules of the Road

By day, a vessel constrained by her draft shows which shape?

  1. A black cone with its apex downward.
  2. A black cylinder. Correct answer.
  3. Three black balls in a vertical line.
  4. Two black balls in a vertical line.

Explanation

A vessel constrained by her draft shows a cylinder by day and three all-round red lights in a vertical line at night. The signal warns other vessels that she cannot safely deviate from her course.

Question 13Rules of the Road

When radar is used to determine whether risk of collision exists, which practice is required?

  1. Plot only targets detected inside two nautical miles.
  2. Treat a steady relative bearing as proof that no risk exists.
  3. Assume risk exists only when the echo grows steadily larger.
  4. Avoid drawing conclusions from scanty radar information. Correct answer.

Explanation

Proper use must be made of radar, including long-range scanning and plotting, and assumptions must not be made on the basis of scanty information, especially scanty radar information. A steady relative bearing is in fact a warning sign of developing risk.

Question 14Rules of the Road

At night, what lights does a vessel engaged in trawling show?

  1. Two all-round red lights in a vertical line.
  2. A red all-round light above a white all-round light.
  3. A green all-round light above a white all-round light. Correct answer.
  4. A white all-round light above a red all-round light.

Explanation

A vessel engaged in trawling shows a green all-round light over a white all-round light, and by day two cones apex together. The green-over-white combination distinguishes trawling from other forms of fishing.

Question 15Rules of the Road

A vessel at anchor, less than 50 meters in length, shows by day:

  1. A black cone, apex downward, forward.
  2. One black ball in the fore part. Correct answer.
  3. Two black balls in the fore part.
  4. A black cylinder in the fore part.

Explanation

A vessel at anchor shows one black ball forward where it can best be seen. A vessel of 50 meters or more shows two black balls, the forward one higher than the after one.

Question 16Rules of the Road

A power-driven vessel underway and a sailing vessel underway are crossing so as to involve risk of collision. Which must keep out of the way?

  1. The power-driven vessel. Correct answer.
  2. The sailing vessel, because she is the more maneuverable of the two.
  3. Neither; both are stand-on vessels in this situation.
  4. Whichever vessel has the wind on her port side.

Explanation

A power-driven vessel underway must keep out of the way of a sailing vessel underway, along with vessels not under command, restricted in their ability to maneuver, fishing, and constrained by draft. The sailing vessel, being the stand-on vessel, keeps her course and speed.

Question 17Rules of the Road

A vessel is overtaking another when she approaches from a direction more than how many degrees abaft the other vessel's beam?

  1. More than 22.5 degrees abaft her beam. Correct answer.
  2. More than 45 degrees abaft her beam.
  3. More than 112.5 degrees abaft her beam.
  4. More than 67.5 degrees abaft her beam.

Explanation

A vessel is deemed to be overtaking when she comes up with another from a direction more than 22.5 degrees abaft the latter's beam, that is, from a position from which she could see only the other's sternlight at night. When in doubt, the vessel is treated as overtaking.

Question 18Rules of the Road

When crossing a traffic separation scheme, a vessel shall:

  1. Cross on a heading as nearly as practicable at right angles to the flow of traffic. Correct answer.
  2. Cross at any convenient angle, giving way to vessels using the lane.
  3. Remain inside the separation zone until a gap in traffic appears.
  4. Cross only near the termination of a lane, next to the separation zone.

Explanation

A vessel using a traffic separation scheme must normally cross the lanes on a heading as nearly as practicable at right angles to the general direction of traffic flow. This keeps the time spent in the lane and the exposure to opposing traffic to a minimum.

Question 19Rules of the Road

A vessel in sight of another vessel fails to understand that vessel's intentions or doubts whether sufficient action is being taken. What signal does she sound?

  1. One prolonged blast followed by three short blasts.
  2. Three short blasts followed by one prolonged blast.
  3. At least five short and rapid blasts. Correct answer.
  4. Two prolonged blasts.

Explanation

When in doubt, or when a vessel fails to understand the intentions of another or doubts that sufficient action is being taken, she sounds at least five short and rapid blasts. The signal may be supplemented by a light signal of at least five short and rapid flashes.

Question 20Rules of the Road

Under the Inland Rules, what sound signal does a vessel use to request the opening of a drawbridge?

  1. One short blast followed by one prolonged blast.
  2. Two short blasts followed by one prolonged blast.
  3. One prolonged blast followed by one short blast. Correct answer.
  4. Five short and rapid blasts.

Explanation

The Inland Rules prescribe one prolonged blast followed by one short blast as the signal requesting a drawbridge opening. The drawtender answers with the same signal when the bridge can be opened immediately.

Question 21Rules of the Road

In fog, what sound signal does a vessel aground make at intervals of not more than two minutes?

  1. One prolonged blast followed by two short blasts on the whistle.
  2. Two prolonged blasts on the whistle separated by an interval of about one second.
  3. Rapid ringing of the bell for about five seconds, with no strokes before or after.
  4. Three strokes on the bell before and after about five seconds of rapid ringing. Correct answer.

Explanation

A vessel aground gives the bell signal of a vessel at anchor, which is rapid ringing for about five seconds, and adds three separate and distinct strokes on the bell immediately before and after that ringing. Inland waters vessels also sound three short blasts on the whistle.

Question 22Rules of the Road

At night, a power-driven vessel towing astern with a tow that exceeds 200 meters in length shows:

  1. Three masthead lights in a vertical line. Correct answer.
  2. Two masthead lights, the after one higher than the forward one.
  3. One masthead light and two all-round red lights.
  4. Two masthead lights in a vertical line.

Explanation

A power-driven vessel towing astern shows two masthead lights in a vertical line, and three in a vertical line when the length of the tow exceeds 200 meters. A vessel towing also carries a yellow towing light in a vertical line above the sternlight.

Question 23Rules of the Road

Two sailing vessels are approaching so as to involve risk of collision, each with the wind on a different side. Which keeps out of the way?

  1. The vessel to windward.
  2. The larger of the two sailing vessels.
  3. The vessel with the wind on her port side. Correct answer.
  4. The vessel with the wind on her starboard side.

Explanation

When two sailing vessels have the wind on different sides, the one with the wind on her port side keeps out of the way of the one with the wind on her starboard side. Where both have the wind on the same side, the vessel to windward keeps clear.

Question 24Rules of the Road

A vessel restricted in her ability to maneuver is engaged in dredging and has an obstruction on her port side. At night she shows, on the side where the obstruction lies:

  1. Two all-round green lights in a vertical line.
  2. Three all-round red lights in a vertical line.
  3. Two all-round red lights in a vertical line. Correct answer.
  4. One all-round red light above one all-round green light.

Explanation

A dredging or underwater-operations vessel with an obstruction on one side shows two all-round red lights in a vertical line on the obstructed side, and two all-round green lights in a vertical line on the side on which another vessel may safely pass. By day the equivalent shapes are two balls and two diamonds.

Question 25Rules of the Road

Two power-driven vessels are in restricted visibility and are detecting each other only by radar. Which statement is correct?

  1. The vessel that first detected the other by radar must keep out of the way.
  2. Both vessels must hold course and speed until the other is sighted visually.
  3. The vessel with the other on her starboard side is the stand-on vessel.
  4. Neither vessel is a stand-on vessel; both must take action in ample time. Correct answer.

Explanation

The steering and sailing rules of the crossing, head-on, and overtaking sections apply only to vessels in sight of one another. In restricted visibility there is no stand-on vessel, and every vessel must take action to avoid a close-quarters situation in ample time.

Question 26Rules of the Road

Under the Rules, which requirement applies to every vessel at all times, whether or not risk of collision exists?

  1. Keep a proper look-out by sight, hearing and all available means Correct answer.
  2. Post a dedicated lookout forward at all times while the vessel is underway at night
  3. Keep the radar on continuous long-range scan whenever the vessel is moving
  4. Maintain a continuous listening watch on the international distress frequency

Explanation

Rule 5 requires every vessel to maintain a proper look-out at all times by sight and hearing as well as by all available means appropriate to the prevailing circumstances. The duty is continuous and is not limited to periods of darkness or to situations where collision risk has already been established.

Question 27Rules of the Road

Two power-driven vessels meet head-on in sight of one another and risk of collision exists. What must each vessel do?

  1. Alter course to starboard and pass port side to port side Correct answer.
  2. Stop engines until the other vessel has passed
  3. Sound one short blast and hold course
  4. Alter course to port so as to open the other vessel's starboard side

Explanation

In a head-on situation each vessel must alter her course to starboard so that they pass port side to port side. This is required unless the vessels are so close that collision cannot be avoided by the give-way action alone.

Question 28Rules of the Road

A vessel in sight of another vessel sounds one short blast. What does this signal indicate?

  1. I intend to overtake you on your starboard side
  2. I am in doubt as to your intentions
  3. I am operating astern propulsion
  4. I am altering my course to starboard Correct answer.

Explanation

One short blast is a maneuvering signal meaning the vessel is altering her course to starboard. Two short blasts mean she is altering to port, and three short blasts indicate astern propulsion.

Question 29Rules of the Road

At night, a vessel not under command exhibits two all-round lights in a vertical line. What color are these lights?

  1. Three green
  2. Two white
  3. Two red Correct answer.
  4. One red over one white

Explanation

A vessel not under command shows two all-round red lights in a vertical line where they can best be seen, in addition to the lights required of a vessel underway when she is making way. The red pair is the identifying signal of that status.

Question 30Rules of the Road

At night, a pilot vessel engaged on pilotage duty shows which all-round lights in a vertical line in addition to her running lights?

  1. Red over red
  2. Red over white
  3. White over red Correct answer.
  4. Green over white

Explanation

A pilot vessel on pilotage duty shows two all-round lights in a vertical line at or near the masthead, the upper white and the lower red. When not on pilotage duty she shows the lights of a vessel of her own size and type.

Question 31Rules of the Road

By day, a vessel aground shows which shape or shapes where they can best be seen?

  1. Two black balls in a vertical line
  2. A black diamond
  3. A black cylinder
  4. Three black balls in a vertical line Correct answer.

Explanation

A vessel aground exhibits the lights or shapes for a vessel at anchor plus, where best seen, three black balls in a vertical line by day and two all-round red lights in a vertical line by night. The three-ball display is unique to the aground condition.

Question 32Rules of the Road

A sailing vessel is underway at night and shows no optional lights. Which lights does she exhibit?

  1. Sidelights and a sternlight Correct answer.
  2. Sidelights only, with a white flare-up when approached
  3. A masthead light, sidelights and a sternlight
  4. Two all-round white lights and a sternlight

Explanation

A sailing vessel underway shows sidelights and a sternlight, and may optionally show two all-round lights in a vertical line, red over green, at or near the masthead. She does not show a masthead light, which is the identifying light of a power-driven vessel.

Question 33Rules of the Road

Two sailing vessels are approaching so as to involve risk of collision and both have the wind on the same side. Which vessel must keep out of the way?

  1. The vessel to windward Correct answer.
  2. The vessel that is closer to the other
  3. The vessel with the wind on her port side
  4. The vessel to leeward

Explanation

When both sailing vessels have the wind on the same side, the vessel to windward must keep out of the way of the vessel to leeward. The port-side rule applies only when the two vessels have the wind on different sides.

Question 34Rules of the Road

When a vessel takes action to avoid collision, which quality does the Rules require of that action?

  1. It must consist solely of a reduction of speed until the other vessel passes clear
  2. It must be positive, timely and consistent with good seamanship Correct answer.
  3. It must be delayed until the other vessel has sounded her maneuvering signal
  4. It must be reported immediately by radiotelephone to the nearest coast station

Explanation

Any action taken to avoid collision must be positive, made in ample time, and have due regard to good seamanship. A hesitant or last-minute maneuver leaves the other vessel uncertain and increases danger.

Question 35Rules of the Road

While risk of collision exists, what is the primary duty of the stand-on vessel?

  1. To sound one short blast and maintain a radar plot
  2. To reduce speed to bare steerageway immediately
  3. To alter course away from the give-way vessel at once
  4. To keep her course and speed Correct answer.

Explanation

The stand-on vessel must keep her course and speed so that the give-way vessel can judge the situation and act predictably. She may act only when it becomes apparent that the give-way vessel is not taking appropriate action.

Question 36Rules of the Road

A vessel has determined that she is the overtaking vessel. What duty does she owe the vessel being overtaken?

  1. She must reduce her speed to less than that of the overtaken vessel
  2. She must sound two prolonged blasts before drawing ahead
  3. She must pass on the vessel's port side
  4. She must keep out of the way until finally past and clear Correct answer.

Explanation

The overtaking vessel must keep out of the way of the vessel being overtaken until she is finally past and clear. A later change in the bearing between the two vessels does not relieve her of that duty.

Question 37Rules of the Road

In a narrow channel, which vessel must not impede the passage of a power-driven vessel that can safely navigate only within the channel?

  1. A power-driven vessel of any length carrying cargo
  2. A vessel engaged in commercial fishing with nets
  3. A sailing vessel or a vessel under 20 meters Correct answer.
  4. A vessel towing a tow of less than 200 meters

Explanation

Rule 9 provides that a vessel of less than 20 meters in length or a sailing vessel shall not impede the passage of a vessel that can safely navigate only within a narrow channel or fairway. Larger power-driven vessels able to navigate outside the channel are not given that protection by this provision.

Question 38Rules of the Road

A power-driven vessel underway must keep out of the way of which of the following vessels?

  1. A seaplane on the water that is landing
  2. A ferry crossing on a regularly scheduled route
  3. A vessel of the same category approaching fine on her port bow
  4. A vessel engaged in fishing Correct answer.

Explanation

The responsibility rule places a power-driven vessel underway below vessels not under command, vessels restricted in their ability to maneuver, vessels engaged in fishing and sailing vessels. She must therefore keep clear of a vessel engaged in fishing.

Question 39Rules of the Road

A vessel at anchor in fog sounds which signal at intervals of not more than one minute?

  1. One prolonged blast followed by two short blasts
  2. Rapid ringing of the bell for about five seconds Correct answer.
  3. Two prolonged blasts with an interval of about two seconds between them
  4. Three short blasts

Explanation

A vessel at anchor in restricted visibility rings the bell rapidly for about five seconds at intervals of not more than one minute. A vessel of 100 meters or more in length also sounds a gong aft, and a vessel aground adds three strokes before and after the bell signal.

Question 40Rules of the Road

Under the Rules, a vessel of 12 meters or more in length must be provided with at least which sound-signal equipment?

  1. A whistle and an efficient sound-signal appliance
  2. A gong, a bell and a whistle
  3. A bell only
  4. A whistle and a bell Correct answer.

Explanation

A vessel of 12 meters or more in length must carry a whistle and a bell. A vessel of 100 meters or more adds a gong, which is sounded aft in restricted visibility.

Question 41Rules of the Road

A power-driven vessel 60 meters in length is underway at night. How many masthead lights does she exhibit, and where?

  1. None, if her sidelights are combined in one lantern
  2. One, at the top of the foremast
  3. Two, one forward and one higher and abaft Correct answer.
  4. Three, if the vessel is over 50 meters

Explanation

A power-driven vessel of 50 meters or more shows two masthead lights, a forward one and a second one abaft of and higher than the forward light, in addition to sidelights and a sternlight. The second masthead light is what distinguishes her at night from a smaller power-driven vessel.

Question 42Rules of the Road

By day, a power-driven vessel towing another vessel shows which shape where it can best be seen?

  1. Two black cones, apexes together
  2. A black ball
  3. A black cylinder
  4. A black diamond Correct answer.

Explanation

A vessel towing shows a black diamond where it can best be seen, and a second diamond if the length of the tow exceeds 200 meters. The diamond identifies the towing vessel by day just as the extra masthead lights do at night.

Question 43Rules of the Road

How is the inshore traffic zone of a traffic separation scheme to be used?

  1. It is reserved exclusively for vessels fishing with nets
  2. Any vessel may use it as an alternative to the traffic lane
  3. Through traffic should not use it if the lane can be used safely Correct answer.
  4. It is closed to all vessels except those in distress

Explanation

A vessel should not use the inshore traffic zone when she can safely use the appropriate traffic lane. Small vessels, sailing vessels and fishing vessels may use the zone, but through traffic belongs in the lane.

Question 44Rules of the Road

At night, a vessel constrained by her draft, underway, shows which additional lights?

  1. One red all-round light over one white all-round light
  2. Three red all-round lights in a vertical line Correct answer.
  3. Three white all-round lights in a vertical line at the masthead
  4. Two red all-round lights in a vertical line

Explanation

A vessel constrained by her draft shows, in addition to the lights for a power-driven vessel underway, three all-round red lights in a vertical line. By day she shows a cylinder where it can best be seen.

Question 45Rules of the Road

A 120-meter vessel at anchor exhibits two all-round white lights at night, one in the fore part and one at the stern. How are they positioned relative to each other?

  1. Both lights on the masthead in a horizontal line
  2. The all-round light at the stern carried higher than the light in the fore part
  3. The light in the fore part higher than the light at the stern Correct answer.
  4. Both lights at the same height, one forward and one aft

Explanation

A vessel at anchor shows an all-round white light in the fore part and a second all-round white light at or near the stern at a lower level. The difference in height helps an approaching vessel judge the anchored vessel's orientation.

Question 46Rules of the Road

A vessel is fishing with trolling lines that do not restrict her maneuverability. How is she treated under the Rules?

  1. As a vessel not under command while the lines are in the water
  2. As a vessel engaged in fishing, entitled to right of way over sailing vessels
  3. As a vessel restricted in her ability to maneuver
  4. As an ordinary power-driven vessel, not privileged as a fishing vessel Correct answer.

Explanation

The definition of a vessel engaged in fishing covers fishing with nets, lines, trawls or other apparatus that restricts maneuverability, and expressly excludes trolling lines or apparatus that does not restrict maneuverability. A troller therefore has no fishing-vessel privileges and must follow the ordinary steering and sailing rules.

Question 47Rules of the Road

A power-driven vessel is proceeding in or near an area of restricted visibility. What must she do with her engines?

  1. Run them at full speed to minimize exposure time
  2. Stop them until visibility improves
  3. Have them ready for immediate maneuver Correct answer.
  4. Use only the engines needed for steering

Explanation

In or near restricted visibility, power-driven vessels must have their engines ready for immediate maneuver. This complements the requirement to proceed at a safe speed and to sound the appropriate fog signals.

Question 48Rules of the Road

A stand-on vessel observes that the give-way vessel is not taking appropriate action and that collision cannot be avoided by that vessel alone. What may the stand-on vessel do?

  1. Reverse her engines and back down at once
  2. Only sound five short blasts and wait
  3. Nothing; she must hold course and speed regardless
  4. Take such action as will best aid to avoid collision Correct answer.

Explanation

When it becomes apparent that the give-way vessel is not taking appropriate action, the stand-on vessel may take action to avoid collision, and must do so if collision cannot be avoided by the give-way vessel alone. She should not, if circumstances admit, alter course to port for a vessel on her own port side.

Question 49Rules of the Road

Under the Inland Rules, a power-driven vessel in a narrow channel intends to overtake another vessel on that vessel's starboard side. Which signal states that intention?

  1. One prolonged blast followed by one short blast
  2. Five short blasts
  3. Two prolonged blasts followed by one short blast Correct answer.
  4. Two prolonged blasts followed by two short blasts

Explanation

Under the Inland Rules, two prolonged blasts followed by one short blast means the vessel intends to overtake on the other vessel's starboard side, and two prolonged followed by two short blasts means the port side. The vessel to be overtaken must indicate her agreement before the maneuver is begun.

Question 50Rules of the Road

Which statement about compass bearings and risk of collision is correct?

  1. A steady bearing always means the other vessel is stopped
  2. Bearings need only be taken when the other vessel is within radar range
  3. Risk of collision cannot exist if the bearing changes by more than five degrees
  4. Risk of collision may exist even when there is an appreciable bearing change Correct answer.

Explanation

A risk of collision is deemed to exist when the compass bearing of an approaching vessel does not appreciably change, but risk may also exist despite an appreciable bearing change, particularly when approaching a very large vessel, a tow, or a vessel at close range. Bearings should therefore be interpreted with caution rather than treated as an absolute test.