Yes. They should always be on for safety.
Navigation lights must be on during periods of restricted visibility.
lights must be on during periods of restriced visibility
On power-driven vessels, navigation lights must be on during periods of restricted visibility.
On power-driven vessels, navigation lights must be on during periods of restricted visibility.
during periods of restricted visibility
Lights must be on during periods of restricted visibility
Lights must be on during periods of restricted visibility
I believe the navigation lighting requirement is that they have to be displayed between sunset and sunrise, and during periods of limited visibility such as fog, rain, or haze.
lights must be on during periods of restricted visibility
500
Lights must be on during periods of restricted visibility. ref: EQ-2
On power-driven vessels, navigation lights must be on during periods of restricted visibility.