Obviously I would have passed safely ahead had I pressed on . .

You can't please everyone, though. There is a convention among mechant ships to alter at 1nm range and this is what I look for. I altered for a ship on my stbd at 1nm, presenting him with my port aspect. When abreast of him and indications were that we would clear I resumed my course, his +90deg. At this point he gave 5 shortblasts and altered violently to stbd. I'm not sure if international signals include slapping the inside of the elbow.
I guess he hadn't seen me at all until that moment.
 
I don't agree with the idea that port turns lead to collision.

A clear course change done well in advance is a safe move, in either direction. I agree that a subtle turn is dangerous, but turning 30 degrees or more seems fine to me. The ship then knows it can carry on as before and you can then start edging back to be as close to the stern as seems sensible (particularly if there are 3 more ships coming up behind)
 
I regret the somewhat sarcastic tone of my original post, and am impressed that none of the (very interesting and helpful) replies so far has taken me to task for it.

As has already been pointed out, there isn't enough information in the letter to determine whether or not the yacht was the stand-on vessel. It does say that it was a daylight crossing from Trebeurden to Falmouth, and that "Within the space of an hour we were mixing with perhaps a dozen ships on their way to/from the Ushant TSS." So he was not far off the French coast and not in a TSS. The author clearly regarded his boat as the stand on vessel and was monitoring the ship's track by its AIS position overlayed on his Navmaster. We know he was going in a northerly direction, but we don't know whether the ship was approaching from the East or the West.

However, my post wasn't intended to be a comment on the wisdom of the author's actions. Rather, it was intended to highlight the distortion of spatial perspective that can occur at sea. Do radar and AIS plots do any more than reinforce this? After he had heaved to, the ship took 5 minutes to cross half a mile in front of him. If he had not heaved to, a yacht speed of 6 knots would have put him under the bows of the ship. A yacht speed of 8 knots would have put him less than 2 cables clear. Hence my view that the remark "Obviously I would have passed safely ahead . . ." may be a mistake. Does having a lot of ships around travelling at 20 knots create the illusion that you are one of them?

Mark

PS I suspect that those advocating alterating course to aim at the stern of an approaching ship would not do so if the ship was approaching from the port side and had just indicated by a blast on its horn that it was altering course to starboard.

PPS Is it "he had heaved to" or "he had hove to"? See Miles Kington aka Dr Wordsmith's warning.
 
[ QUOTE ]
PS I suspect that those advocating alterating course to aim at the stern of an approaching ship would not do so if the ship was approaching from the port side and had just indicated by a blast on its horn that it was altering course to starboard.

Agreed, with the important bit of the sentence being, "just indicated by a blast on its horn that it was altering course to starboard". I'd still be looking around though, to see which ship it had altered course for, as I'd be surprised if the alteration with sound signal was for me.



[/ QUOTE ]
 
[ QUOTE ]
I suspect that those advocating alterating course to aim at the stern of an approaching ship would not do so if the ship was approaching from the port side and had just indicated by a blast on its horn that it was altering course to starboard

[/ QUOTE ]

Agree, or if the ship made an early course alteration which would render such a move unnecessary
 
Thanks for expanding the quote.

You bring up the interesting question of whether AIS helps or hinders range judgement . . .

He was in a strong tidal stream area. Was his display ground stabilised or yacht stabilised? And if yacht stabilised, stabilised to track or to heading? These are frequent causes for mistakes in judging miss distances. We don't know, of course.

Or was he using Mk 1 eyeball and compass to judge the collision risk (the only 100% method)? Or was visibility poor, and he relying on his screen? If so, of course, sail does not have right of way over a starboard approaching motor vessel.

Interesting can of worms.
 
[ QUOTE ]
If so, of course, sail does not have right of way over a starboard approaching motor vessel.


[/ QUOTE ] /forums/images/graemlins/confused.gif Suggest you read colregs then


Rule 18


Responsibilities Between Vessels

Except where rule 9, 10, and 13 otherwise require:

(a)A power driven vessel underway shall keep out of the way of:


(iv)a sailing vessel;
 
Sorry, are you saying that you think that colregs state that sail is not the stand-on vessel in poor visibility?

Where do colregs say that?
 
Yes this is what I have been taught. Rule 19, basically. Rule 18 as quoted above is only valid "to vessels in sight of one another."

However, I am aware that some claim if both vessels use radar they are basically in view of each other and rule 19 does not apply. So this could of course be argued here, AIS and all.
 
[ QUOTE ]
However, I am aware that some claim if both vessels use radar they are basically in view of each other and rule 19 does not apply.

[/ QUOTE ]

Such a claim must surely be refuted. Rule 19 (d) states:
"A vessel which detects by radar alone [my emphasis] 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 in course, so far as possible the following shall be avoided:
(i) An alteration of course to port for a vessel forward of the beam, other than for a vessel being overtaken;
(ii) An alteration of course toward a vessel abeam or abaft the beam."

OK, so this doesn't specifically mention the possibility that both vessels may have detected each other by radar, but to argue that in those circumstances rule 18 applies is absurd. Who has a radar system that can distinguish between a vessel not under command, a vessel restricted in her ability to maneuver, a vessel engaged in fishing, and a sailing vessel, not to mention a vessel motorsailing and flying an inverted cone?

Edit: Oh, and rule 3(k) states in plain English: Vessels shall be deemed to be in sight of one another only when one can be observed visually from the other.

Mark
 
Yes. However, there is a slight difference between using radar and using radar with AIS, as AIS provides some indication that the other vessel can see you as well, while without it you do not know if the other vessel has radar, too.

Of course, colregs would have to be amended with a rule covering AIS (as they did with radar, I guess).

AIS does have the capability of indicating whether a vessel is out of command and things like that, does it not? I am just presuming, don't really know much about it.
 
Good to see that at least some sailors are aware that vessels not in sight of one another obey different colregs to those in sight of one another!

Moral for sail boats in poor visibility, especially at night:

If you're crossing a traffic lane (not necessarily a TSS) with vessels coming from starboard, they'll be on radar watch, and will be expecting you to give way until (if) they see you. Therefore a prudent sailor in this situation will hoist his cone, set a steaming light, lower his jib and notionally (if not actually) run under engine. Then there will be fewer sudden periods of uncertainty about who should be doing what when vessels do see each other . . .

Different issue if vessels are coming from port. Those guys will have altered course long before you see them - which is why sail boats have far fewer 'collision risk' panics coming from their port side. Or hadn't you noticed?

Cue lots of angry people saying 'you should keep away from the busy commercial traffic'. Hmm. How do you cross the channel then?
 
[ QUOTE ]
Sorry, are you saying that you think that colregs state that sail is not the stand-on vessel in poor visibility?

Where do colregs say that?

[/ QUOTE ]

Rule 19

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

(i) An alteration of course to port for a vessel forward of the beam, other than for a vessel being overtaken;

(ii) An alteration of course toward a vessel abeam or abaft the beam.

(e) Except where it has been determined that a risk of collision does not exist, every vessel which hears apparently forward of her beam the fog signal of another vessel, or which cannot avoid a close-quarters situation with another vessel forward of her beam, shall reduce her speed to be the minimum at which she can be kept on her course. She shall if necessary take all her way off and in any event navigate with extreme caution until danger of collision is over.
 
[ QUOTE ]
How do you cross the channel then?

[/ QUOTE ]

Well, you could turn south, then west, then south, then west then north and finally end up on the other side. /forums/images/graemlins/confused.gif
 
This is drifting dangerously close to the rocky waters of Colregs threads, but hey, it stimulates us to check the Colregs, and boy, isn't it amazing how quickly one forgets inconvenient parts of them. Show me a sailor who is claims to be a stickler for the regs, and I'll show you one who fails (at least occasionally) to comply with rule 25(e).

To go back to the original letter-writer's quote, I now spot another ambiguity: "the ship gave a long blast on his hooter". The Colregs, of course (doesn't everyone know them off by heart) define the term "short blast" as a blast of about one second's duration, and the term "prolonged blast" as a blast from four to six seconds' duration . . . .

Aw shutup, Mark, there's work to be done.

Mark
 
As a non-radar person, I stand corrected, and I'm afraid I have therefore only ever considered myself in an actual potential collision situation when in sight of other vessels. In fog, I just worry a bit.

In practice, as I said above, I never stand on the colreg principle of steam giving way to sail with ships (or fishing boats), especially when crossing shipping lanes, whether in a TSS or not.
 
[ QUOTE ]

(e) Except where it has been determined that a risk of collision does not exist, every vessel which hears apparently forward of her beam the fog signal of another vessel, or which cannot avoid a close-quarters situation with another vessel forward of her beam, shall reduce her speed to be the minimum at which she can be kept on her course. She shall if necessary take all her way off and in any event navigate with extreme caution until danger of collision is over.

[/ QUOTE ]

Try telling that to the skippers of some container ships on a tight schedule!
 
Colregs debates inevitably seem to focus on the narrow issue of conflicting interpretations of the rules relating to close quarters situations and tend to lose sight of the broader principles set out in Rule 8 and paraphrased by Al_Jones' comments to avoid getting into those situations.
 
You must log in or register to reply here.

Share this page

Top