Everett wrote:

from the COLREGS http://www.oz.net/~papillon/kbmanual/colregs.html

"Rule 4
Application

"Rules in this section apply to any condition of visibility."

That seems to say it all.

To say what, exactly?

The pecking order (rule 18), stand-on (rule 17), and give-way (rule
16) stuff is not in section I of part B, to which rule 4 refers, but
in section II of part B, which is introduced by rule 11:

"Rules in this section apply to vessels in sight of one another."

So the pecking order *only* applies when in sight.

Section III which is rule 19 applies only to vessels not in
sight of one another, when in restricted visibility. This means
that, even where visibility is restricted (for any reason), as
soon as ships come close enough to see each other, section III
goes out the window and section II kicks in, restoring pecking
order *which does not exist in section III*. But this revived
pecking order may be academic if by then vessels are already
in a close quarters situation.