Collision Avoidance, Cones of Uncertainty, and Appropriate CPA

[evm1024]

Originally Posted by Jim Cate

Interesting! So we now have a new classification: LAFI... License assisted f'n idiots.

The language evolves to meet new requirements!

Jim

LOL - and thus it is.

When I sat for my masters license the most difficult test was on rules of the road. Passing on the others was 70%. Passing on rules was 90%. Miss 4 out of 30 and you failed.

The best definition of professional I have ever heard was simply someone who was paid for the job. Noting about skills, understanding or such.

To assume that all professional mariners are experts is foolish. To assume that they will look out for us small boaters is stupid. To think that we as small boaters do not need to know or follow the rules is crazy. To tell people that we don't really need any aids to navigation other than our eyes is culpable.

This website (acts projects and CF too of course) is a valuable resource for all who would (and should) know the rules better. I know that I will take the course to refresh and improve my understanding of the rules.

The rules define how you should react to a crossing situation. And as the site indicates they are hard to understand in their fullness.


My favorite rules brain teaser:

You are on a river just stemming the current. You are abreast a buoy neither moving ahead of it or behind of it. As you sit there next to the buoy a boat drifts down on you and smacks into your bow. Who is at fault?

[StuM]

Originally Posted by evm1024

My favorite rules brain teaser:

You are on a river just stemming the current. You are abreast a buoy neither moving ahead of it or behind of it. As you sit there next to the buoy a boat drifts down on you and smacks into your bow. Who is at fault?

Are you in waters connected to the high seas navigable by seagoing vessels?
If so, is the waterway covered by any "special rules" in accordance with COLREGS Rule 1b?

If not, what country are you in?

[evm1024]

Originally Posted by StuM

Are you in waters connected to the high seas navigable by seagoing vessels?
If so, is the waterway covered by any "special rules" in accordance with COLREGS Rule 1b?

If not, what country are you in?

Let's put it in waters governed by COLREGS or US Inland rules. They are the same in this case.

[Exile]

Originally Posted by ramblinrod

Obviously, the laws of the sea indicate that commercial vessels are held to a higher level of navigation expertise than rec boats.

While generally speaking it is probably correct that (many if not most) commercial vessels have a higher level of navigation expertise, it's my understanding that all vessels are held to the same level of responsibility to know & apply the Rules properly. So I believe your statement may be misleading if not incorrect.

A rather well-known case that comes to mind was that of a singlehander in a small recreational vessel who was run down from behind by a large commercial ship in open ocean at night. As I recall, it was undisputed that the seas, weather & visibility were fine, and the singlehander was under sail. If I remember correctly, the singlehander (who survived to testify) was running a proper stern light, was down below but not asleep at the time, and was obviously the stand on vessel. It was before AIS was available for rec boats, and I don't recall whether the small vessel was running radar. Not surprisingly, the court held the large commercial ship liable for not maintaining a proper lookout, but surprisingly (to me) apportioned liability to the singlehander for also not having a proper lookout. It's been awhile since I read the case, but it suggests that the same standard applies, and distinctions are not made based on the size, status and/or speed of different types of vessels.

I hope Dockhead or someone else will correct me if I have the facts or the courts analysis/conclusion wrong. (Sorry, can't remember the name of the case).

[evm1024]

Originally Posted by evm1024

SNIP!

My favorite rules brain teaser:

You are on a river just stemming the current. You are abreast a buoy neither moving ahead of it or behind of it. As you sit there next to the buoy a boat drifts down on you and smacks into your bow. Who is at fault?

The short answer is that you are at fault.

By coming stemming the current (river or tidal) and having 0 speed relative to the buoy (SOG = 0) you are still moving through the water.

If the current is 2 kts then you are going 2 kts. The boat that "drifts" down on you is actually going (oh say) 1.75 kts. Thus you are overtaking the other boat and failed to give way to the overtaken boat (rule 13).

The primary point (at least when I learned it) was that it is easy to misunderstand the situation and that you do need to think about the rules and how they apply.

Oh, and on the Columbia River this happens every year or so.


PS

Of course when I say that you are at fault I mean in the majority of fault. As noted in prior posts if there is a collision both parties are at fault. The degree of fault (and who pays or goes to jail) is determined by what actually happened. In the case of the "drifting" boat. They failed to keep a lookout and failed to take action to avoid a collision (rule 17). But the major fault lies with the boat next to the buoy.

[TeddyDiver]

Originally Posted by Exile

While generally speaking it is probably correct that (many if not most) commercial vessels have a higher level of navigation expertise, it's my understanding that all vessels are held to the same level of responsibility to know & apply the Rules properly. So I believe your statement may be misleading if not incorrect.

A rather well-known case that comes to mind was that of a singlehander in a small recreational vessel who was run down from behind by a large commercial ship in open ocean at night. As I recall, it was undisputed that the seas, weather & visibility were fine, and the singlehander was under sail. If I remember correctly, the singlehander (who survived to testify) was running a proper stern light, was down below but not asleep at the time, and was obviously the stand on vessel. It was before AIS was available for rec boats, and I don't recall whether the small vessel was running radar. Not surprisingly, the court held the large commercial ship liable for not maintaining a proper lookout, but surprisingly (to me) apportioned liability to the singlehander for also not having a proper lookout. It's been awhile since I read the case, but it suggests that the same standard applies, and distinctions are not made based on the size, status and/or speed of different types of vessels.

I hope Dockhead or someone else will correct me if I have the facts or the courts analysis/conclusion wrong. (Sorry, can't remember the name of the case).

You are right, I remember it was ruled 50/50 fault for both.. The single hander got some money from the shipping company about 50% of the true value of his boat. No criminal charges what I know of..

[nigel1]

Originally Posted by evm1024

The short answer is that you are at fault.

By coming stemming the current (river or tidal) and having 0 speed relative to the buoy (SOG = 0) you are still moving through the water.

If the current is 2 kts then you are going 2 kts. The boat that "drifts" down on you is actually going (oh say) 1.75 kts. Thus you are overtaking the other boat and failed to give way to the overtaken boat (rule 13).

The primary point (at least when I learned it) was that it is easy to misunderstand the situation and that you do need to think about the rules and how they apply.

Oh, and on the Columbia River this happens every year or so.


PS

Of course when I say that you are at fault I mean in the majority of fault. As noted in prior posts if there is a collision both parties are at fault. The degree of fault (and who pays or goes to jail) is determined by what actually happened. In the case of the "drifting" boat. They failed to keep a lookout and failed to take action to avoid a collision (rule 17). But the major fault lies with the boat next to the buoy.

Ah, but this would only be the case if the drifting vessel presented a stern aspect, by definition, you are only overtaking when coming up with another vessel from a direction more than 22.5 degrees abaft her beam.

[ramblinrod]

This thread was started by one individual who is keen on learning high level navigation practices as used on the bridges of large commercial vessels, and employing them on a recreational yacht.

Kudos to them.

However, I vehemently object to the suggestion that everyone else must do so "to be safe".

In my opinion this entire notion is false.

Keeping a proper watch and using rudimentary navigation skills and common sense to follow Colregs, will keep you safe from a collision avoidance perspective.

It simply isn't that complicated.

Nobody needs any additional guide or skills to be "safe" from a collision avoidance perspective.

It simply isn't so.

You can access Colregs here.

http://www.jag.navy.mil/distrib/inst...OLREG-1972.pdf

Read them, learn them, practice them, and you'll be absolutely fine.

[ramblinrod]

Originally Posted by transmitterdan

Well Rod suggested that a big ship should act as give way vessel even if they are the stand on. I can't square that suggestion with "all complying with Colregs a given". Either we all comply with the Colregs or we don't. Can't have it both ways.

No I didn't.

I believe all vessels should comply with Colregs, always.

Some have argued, that per Colregs, "risk of collision exists when a constant bearing to another vessel has been determined".

Well, perhaps by the letter of the law, maybe, but was it really intended to mean this, if this constant bearing was discovered 100 miles away and the vessels are travelling 0.1 knots? Does it even have to be 2 miles away? 500 ft?

The point is, everyone needs to apply some common sense.

If a large fast moving ship spots a rec vessel many miles away, that could pose a risk of collision at some point (everything else being equal), before the situation is truly a "risk" they are free to navigate as they please, such that the potential future "risk" is diminished.

If this means the "risk" that they may have to reduce speed is minimized, there is financial justification to do so. This is why "early action" even earlier than required by any Colregs provision is prudent for commercial vessels.

Really it is just common sense for everyone; if you can navigate your vessel in such a way that a "risk of collision" does not "truly" develop, do so.

It is that simple.

It's all just common sense.

[Exile]

Originally Posted by ramblinrod

This thread was started by one individual who is keen on learning high level navigation practices as used on the bridges of large commercial vessels, and employing them on a recreational yacht.

Kudos to them.

However, I vehemently object to the suggestion that everyone else must do so "to be safe".

In my opinion this entire notion is false.

Not just your opinion Rod, but everyone else's as well. I don't recall anyone ever stating, suggesting or implying that recreational sailors need to learn "high level navigation practices as used on the bridges of large commercial vessels . . . to be safe." My takeaway from this thread is that, "to be safe," one must avoid the types of close-in maneuvers you have explicitly & repeatedly tried to justify (and not as hypotheticals I should add), and to avoid the seat-of-the-pants maneuvers that are the result. My other takeaway is that there's nothing wrong with encouraging those who have the need or interest to hone their skills, and using examples from what clearly not to do, all the way up to what may be best practices in complex waterways such as the English Channel.

Keeping a proper watch and using rudimentary navigation skills and common sense to follow Colregs, will keep you safe from a collision avoidance perspective.

Agreed, most of the time anyway.

It simply isn't that complicated.

No it's not. Which begs the question why you have had it so wrong at times.

Nobody needs any additional guide or skills to be "safe" from a collision avoidance perspective.

Some people need to believe they already know it all, whereas others always feel they have more to learn regardless of expertise.

It simply isn't so.

You can access Colregs here.

http://www.jag.navy.mil/distrib/inst...OLREG-1972.pdf

Read them, learn them, practice them, and you'll be absolutely fine.

Good advice!

Originally Posted by ramblinrod

No I didn't.

I believe all vessels should comply with Colregs, always.

That's a good start, but you seem to still have some confusion whether "all vessels" are held to the same standard.

Some have argued, that per Colregs, "risk of collision exists when a constant bearing to another vessel has been determined".

No, it's when there's a constant bearing and distances that are closing when a risk of collision may exist.

Well, perhaps by the letter of the law, maybe, but was it really intended to mean this, if this constant bearing was discovered 100 miles away and the vessels are travelling 0.1 knots?

No.

Does it even have to be 2 miles away?

With a constant bearing and a closing distance, then at 2 miles a potential risk of collision absolutely exists. And in many instances, an actual risk of collision exists requiring a stand on vessel to maneuver if the give way vessel has not already done so.

500 ft?

The Rules require both vessels to maneuver so as to avoid collision.

The point is, everyone needs to apply some common sense.

There's usually no conflict between common sense and a reasonable understanding & proper application of the Rules.

If a large fast moving ship spots a rec vessel many miles away, that could pose a risk of collision at some point (everything else being equal), before the situation is truly a "risk" they are free to navigate as they please, such that the potential future "risk" is diminished.

Correct, i.e. before a "potential" risk has developed. Some of which is a judgement call (subjective) so long as it comports with the reasonably objective standard which the Rules make mandatory. You seem to have left off confused about this when discussed previously.

If this means the "risk" that they may have to reduce speed is minimized, there is financial justification to do so. This is why "early action" even earlier than required by any Colregs provision is prudent for commercial vessels.

Motivations are irrelevant since they cannot be ascertained by the other vessel. So long as the action is early enough the vessel is free to maneuver, regardless of its motivation in doing so.

Really it is just common sense for everyone; if you can navigate your vessel in such a way that a "risk of collision" does not "truly" develop, do so.

Exactly. But at the same time baffling why you would propose not maneuvering until X no. of feet on the grounds that you didn't want to interfere with the big ship's last minute maneuver.

It is that simple.

Not for many, apparently, or we wouldn't be having such lengthy discussions.

It's all just common sense.

If only . . . .

[evm1024]

Originally Posted by nigel1

Ah, but this would only be the case if the drifting vessel presented a stern aspect, by definition, you are only overtaking when coming up with another vessel from a direction more than 22.5 degrees abaft her beam.

It is implicit in the phrase "drifts down on you" that the other boat is more or less dead ahead of you. Being that there is a current both boats are aligned to the current. And even if the boat ahead was doing 0 kts you are still the overtaking vessel.

This is why the brain teaser was presented by the local coasties. They point out that we as mariners tend to look at boating interactions is biased ways (next to buoy therefore we are not moving etc). And that we need to apply the rules to the situation.

Sorry to all for the thread drift - back to our normal channel.

[Juho]

Originally Posted by evm1024

The short answer is that you are at fault.

By coming stemming the current (river or tidal) and having 0 speed relative to the buoy (SOG = 0) you are still moving through the water.

If the current is 2 kts then you are going 2 kts. The boat that "drifts" down on you is actually going (oh say) 1.75 kts. Thus you are overtaking the other boat and failed to give way to the overtaken boat (rule 13).

The primary point (at least when I learned it) was that it is easy to misunderstand the situation and that you do need to think about the rules and how they apply.

Oh, and on the Columbia River this happens every year or so.


PS

Of course when I say that you are at fault I mean in the majority of fault. As noted in prior posts if there is a collision both parties are at fault. The degree of fault (and who pays or goes to jail) is determined by what actually happened. In the case of the "drifting" boat. They failed to keep a lookout and failed to take action to avoid a collision (rule 17). But the major fault lies with the boat next to the buoy.

Just wondering if I could use the rules better to my advantage.

= = = = =
Option 1.
= = = = =
What if I turn the boat 180° and use reverse gear to keep the boat stationary? Then it might be the other boat that is overtaking me.

From the colregs.
> Rule 13
> Overtaking
> (a). Notwithstanding anything contained in the Rules of part B, sections I and II, any vessel overtaking any other shall keep out of the way of the vessel being overtaken.
> (b). A vessel shall be deemed to be overtaking when coming up with another vessel from a direction more than 22.5 degrees abaft her beam, that is, in such a position with reference to the vessel she is overtaking, that at night she would be able to see only the sternlight of that vessel but neither of her sidelights.

It seems that if both vessels "come up with the other vessel" backwards, they both should keep out of the way. That could mean a 50-50 responsibility. Both vessels would move backwards in different ways (drifting vs stationary but moving against the stream).

= = = = =
Option 2.
= = = = =
Nowadays some vessels have the capability of staying in one place with the help of motors and computers. I wonder if I would be allowed to use this technique for motor assisted anchoring. I'd lift the anchor ball and use anchor light to signal to others that I'm anchored. That would make the other vessel responsible of the collision. That is, if I'm allowed to anchor this way.

From the colregs.
> Rule 3
> General definitions
> (i). The word “underway” means that a vessel is not at anchor, or made fast to the shore, or aground.

I'm not aware of any better definition of anchoring in the colregs. If it is not well defined, and I have signalled that I'm anchored, and behave as an anchored vessel should behave (stay stationary), I could say that I am anchored. Or should I throw out an additional small toy anchor to be officially anchored?

> Rule 5
> Look-out
> Every vessel shall at all times maintain a proper look-out by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision.

This rule seems to apply also to anchored vessels (?). But if I'm sleeping or not even in the boat, I could say that "the prevailing circumstances and conditions" were such that I wasn't required to maintain look-out. Leaving the boat alone, motors running, could be risky. But if the system is reliable, then why not. Maybe the motor assisted approach is more reliable than traditional anchors that tend to drag every now and then.

[StuM]

Originally Posted by Juho

From the colregs.
> Rule 3
> General definitions
> (i). The word “underway” means that a vessel is not at anchor, or made fast to the shore, or aground.

I'm not aware of any better definition of anchoring in the colregs. If it is not well defined, and I have signalled that I'm anchored, and behave as an anchored vessel should behave (stay stationary), I could say that I am anchored. Or should I throw out an additional small toy anchor to be officially anchored?

I wouldn't think that COLREGS needed to define "at anchor". If you are affixed to the bottom by an anchor (q.v.), you are "at anchor". If you are not, you are not.

[Juho]

Originally Posted by StuM

I wouldn't think that COLREGS needed to define "at anchor". If you are affixed to the bottom by an anchor (q.v.), you are "at anchor". If you are not, you are not.

I'm afraid you may be right. The court might not accept my explanation.

This would effectively be a ban of "motor assisted anchoring". I would need to maintain look-out and be ready to move if someone drifts or sails in my direction.

If being at anchor means that we must have an anchor at the bottom, we may have some further problems. The rule may not be quite accurate. If I'm connected to a buoy, does the rule say that I'm "underway"? If I'm not "underway", maybe being at anchor could mean (more generally) to be connected to something stationary by something, e.g. by a rope to a buoy, to a cable above me, or to a pole in the sea. But whatever the connection is, it would maybe have to be mechanical, i.e. not computer and motoring based.

From the colregs.
> (i). The word “underway” means that a vessel is not at anchor, or made fast to the shore, or aground."

I also note that connecting my boat to a large ship on the sea might make me a “vessel restricted in her ability to manoeuvre”, but I might still need to maintain look-out, and be considered to be "underway". Is this correct?

[StuM]

As I see it, if an buoy is "anchored" and you are attached to the buoy by a cable, you are also "at anchor"/