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 which 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 Regulations.
This rule details specifically when navigation lights should be exhibited on any vessel. However, most commercial ships never switch their navigation lights off once they are underway, which could be argued that they are complying with paragraph (c), as they deem it to be necessary to show them at all times. This could be likened to driving a car. Car headlights are turned on when it’s dark, during the day when it’s foggy or raining (restricted visibility) and if you drive a Volvo, they’re on all the time!
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