Skip to main content
CaptainsGround
Every answer cited & verifiedAll 4 USCG exam modulesReviewed by a former NMC exam writer
USCG Exam PracticeRule 23 — Power-driven Vessel Underway (lights)

A power-driven vessel is operating on the Great Lakes at night. Which substitution for the standard underway lights prescribed in Rule 23(a) is authorized?

  1. A. An all-round white light may be carried in lieu of the forward masthead light and sidelights
  2. An all-round white light may be carried in lieu of the second masthead light and sternlight, placed in the position of the second masthead lightCorrect
  3. C. An all-round white light and sidelights may be carried in lieu of all lights prescribed in paragraph (a)
  4. D. A flashing yellow all-round light may be substituted for the sternlight

Why B is correct

33 CFR §83.23(e) specifically authorizes a power-driven vessel operating on the Great Lakes to carry an all-round white light in lieu of the second masthead light and sternlight, placed in the position of the second masthead light and visible at the same minimum range. Option C describes the alternative for vessels under 12 meters per §83.23(d), which is a separate provision.

More Rule 23 — Power-driven Vessel Underway (lights) questions

Start drilling in 30 seconds. Free.

No signup, no credit card — answer 5 real, cited exam questions right now.

A power-driven vessel is operating on the Great Lakes at night. Whi… — USCG Exam Practice · CaptainsGround