Exam frequency
65%
Difficulty
3/5
Drill questions
66
Authoritative sources
Every answer on this topic traces back to the public rule corpus below.
Source excerpts
33 CFR §83.30
§ 83.30 § 83.30 Vessels anchored, aground and moored barges (Rule 30). (a) A vessel at anchor shall exhibit where it can best be seen: (i) In the fore part, an all-round white light or one ball; (ii) At or near the stern and at a lower level than the light prescribed in paragraph (i) of this Rule, an all-round white light. (b) A vessel of less than 50 meters in length may exhibit an all-round white light where it can best be seen instead of the lights prescribed in paragraph (a) of this Rule. (c) A vessel at anchor may, and a vessel of 100 meters or more in length shall, also use the available working or equivalent lights to illuminate her decks. (d) A vessel aground shall exhibit the lights prescribed in paragraph (a) or (b) of this Rule and in addition, if practicable, where they c…
COLREGs Rule 20
COLREGs Rule 20 — Application (a) Rules in this Part shall be complied with in all weathers. (b) The Rules concerning lights shall be complied with from sunset to sunrise, and during such times no other lights shall be exhibited, except such lights as cannot be mistaken for the lights specified in these Rules or do not impair their visibility or distinctive character, or interfere with the keeping of a proper look-out. (c) The lights prescribed by these Rules shall, if carried, also be exhibited from sunrise to sunset in restricted visibility and may be exhibited in all other circumstances when it is deemed necessary. (d) The Rules concerning shapes shall be complied with by day. (e) The lights and shapes specified in these Rules shall comply with the provisions of Annex I to these Regula…
COLREGs Rule 21
COLREGs Rule 21 — Definitions (a) “Masthead light” means a white light placed over the fore and aft centerline of the vessel showing an unbroken light over an arc of the horizon of 225 degrees and so fixed as to show the light from right ahead to 22.5 degrees abaft the beam on either side of the vessel. (b) “Sidelights” means a green light on the starboard side and a red light on the port side each showing an unbroken light over an arc of the horizon of 112.5 degrees and so fixed as to show the light from right ahead to 22.5 degrees abaft the beam on its respective side. In a vessel of less than 20 meters in length the sidelights may be combined in one lantern carried on the fore and aft centerline of the vessel. (c) “Sternlight” means a white light placed as nearly as practicable at the …
COLREGs Rule 22
COLREGs Rule 22 — Visibility of Lights The lights prescribed in these Rules shall have an intensity as specified in Section 8 of Annex I to these Regulations so as to be visible at the following minimum ranges: (a) In vessels of 50 meters or more in length: − a masthead light, 6 miles; − a sidelight, 3 miles; − a sternlight, 3 miles; − a towing light, 3 miles; − a white, red, green or yellow all-round light, 3 miles. (b) In vessels of 12 meters or more in length but less than 50 meters in length: − a masthead light, 5 miles; except that where the length of the vessel is less than 20 meters, 3 miles; − a sidelight, 2 miles; − a sternlight, 2 miles; − a towing light, 2 miles; − a white, red, green or yellow all-round light, 2 miles. (c) In vessels of less than 12 meters in length: − a masth…
COLREGs Rule 23
COLREGs Rule 23 — Power-driven Vessels Underway (a) A power-driven vessel underway shall exhibit: (i) a masthead light forward; (ii) a second masthead light abaft of and higher than the forward one; except that a vessel of less than 50 meters in length shall not be obliged to exhibit such light but may do so; (iii) sidelights; and (iv) a sternlight. Power-driven vessel underway. Same for Inland. Relationship to the Inland Rules: Inland Rule 23 differs from this rule — compare against 33 CFR 83.23 before answering a question that turns on which set applies.
COLREGs Rule 29
COLREGs Rule 29 — Pilot Vessels (a) A vessel engaged on pilotage duty shall exhibit: (i) at or near the masthead, two all-round lights in a vertical line, the upper being white and the lower red; (ii) when underway, in addition, sidelights and a sternlight; (iii) when at anchor, in addition to the lights prescribed in subparagraph (i), the light, lights or shape prescribed in Rule 30 for vessels at anchor. (b) A pilot vessel when not engaged on pilotage duty shall exhibit the lights or shapes prescribed for a similar vessel of her length. Vessel engaged on pilotage duty—underway. Same for Inland. Relationship to the Inland Rules: Inland Rule 29 differs from this rule — compare against 33 CFR 83.29 before answering a question that turns on which set applies.
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A vessel of 30 meters in length is at anchor at night. Which lighting option is permitted under the Inland Navigation Rules?
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