Conduct in restricted visibility

In plain language

Rule 19 governs vessels not in sight of one another in or near restricted visibility — so the give-way/stand-on system is switched off and every vessel must act. Proceed at a safe speed with engines ready for immediate maneuver. If you detect a vessel by radar alone and must alter course, avoid turning to port for a vessel forward of your beam (unless overtaking her) and avoid turning toward a vessel abeam or abaft the beam. Hear a fog signal apparently forward of your beam? Slow to bare steerage way and navigate with extreme caution until the danger is over.

Easily confused with

• Rule 17 — Action by stand-on vessel

  There is no stand-on vessel in fog: Rules 11–18 apply only in sight of one another. Under Rule 19 every vessel maneuvers.