Today we are dealing with scenarios due to RESTRICTED VISIBILITY where vessels even though they are not in sight of each other still can cause collisions due to restricted visibility.

Common sense tells you to proceed with caution so that you can adapt a safe speed at all times in restricted visibility scenarios.

If a vessel is using RADAR to detect the potential collision with another vessel, then that vessel shall take avoiding action as soon as possible.

If this avoiding action requires actual alteration of the course it is on, then the following actions should be avoided.

If the alteration of course to PORT for a vessel forward of the beam, other than for a vessel being overtaken occurs then alteration of course should be avoided.

Second scenario is when an alteration of course toward a vessel abeam or abaft of the beam occurs.

Of course like most government agencies it requires the following diagram to discuss these two scenarios.

Hopefully this clears up the above discussion!

Hugh Simpson