Rule 19(d)- Restricted Visibility question

Rule 19(d) states
"(d) A vessel which detects by radar alone the presence of another vessel shall determine if a close-quarters situation is developing and/or risk of collision exists. If so, she shall take avoiding action in ample time, provided that when such action consists of an alteration of course, so far as possible the following shall be avoided:

(i) an alteration of course to port for a vessel forwards of the beam, other than for a vessel being OVERTAKEN"

Note the words “a vessel being OVERTAKEN”. I am fighting a losing battle as everyone is under the assumption that the Rules got the wording wrong on this section. I have always heard this ruled explained that in low viz, a vessel overtaking can alter to port (as would be the case if vessels were in sight). However I believe that the rules are deliberate with their wording specifying that only a vessel being overtaken in restricted visibility can turn to port.

Why would a vessel that is being overtaken be allowed a special privilege to alter course to port in restricted vis? Overtaking situations are only deemed to exist when vessels are in sight (rule 13 is in the ‘in sight’ section). Farwell’s is not helpful in this questions as the wording in section 19(d) is glossed over and is instead used as an opportunity to define ‘radar alone’ and action to avoid collision.

Maybe someone has some knowledge of where this section came about and what exactly deems a vessel to be overtaken in restricted vis. I’d like some insight on how this rule practically applies. Thanks!

The vessel being overtaken does not have a vessel forward of the beam by definition. All of sect (i) is actions taken by the vessel that has a vessel forward of its beam.

But yes it could be written better.

The wording is “for vessel being overtaken”.

This is from Farwell’s 6th Ed:

Vessel C alters to stbd, Vessel D may alter to port or stbd.

Ahh this is more clear and backs up how the rule is normally interpreted. Interestingly, my edition does not have that diagram. I suppose the wording could be interpreted as “when a vessel is being overtaken, the overtaking vessel may alter to port…” This makes sense because the forward vessel is not to alter towards the vessel abaft her beam. The vessel abaft may be more inclined to alter to port to open CPA/ avoid Close Quarters in this situation, though for any other situation a port turn may be disastrous.

A separate breakout of this manuever would probably clear it up.

There’s a bit more on the next page, a little ambiguity in rules with regards to “overtaking” when the vessels are in restricted visibilty.

You better have your shit right while overtaking, good visibilty or not .More often than not , I pulled the throttles back. Especially in narrow channels and low visability.

Your misunderstanding is, I believe, from a grammatical standpoint.
The subject matter is “(d) a vessel which detects by radar alone” . . . “shall take avoiding action in ample time” . . .“provided that when such action consists of an alteration of course”. . .“the following shall be avoided”. . .“an alteration of course to port”. . .other than for [another] vessel being overtaken".

In other words, don’t turn left, for a vessel fwd of the beam, unless you are going to pass them on their port side. :facepunch: :call_me_hand: :+1: