Sailing vessel and RORO ship on collision courses - what do you think of the outcome?

[boatman61]

Originally Posted by jmh2002

Actually no, I was just correcting your incorrect statement regarding the COLREGS.

I'll repeat it again as you still don't seem to get it (nothing to do with aft or abaft) and it's important not to confuse other cruisers.

You wrote the following:



I corrected you because that is wrong. Rule 13 actually says (using your words):

"the boat that's 'more than 22.5 degrees' aft the beam is potentially an overtaking vessel"

You completely missed a key part of Rule 13 that I have highlighted in red.

So I posted a diagram to show how a boat can be 'aft of the beam' (your words) but is in fact a crossing vessel (and therefore NOT an overtaking vessel).

If you know the COLREGS please stop posting half truths and falsehoods that others may understand to be correct.

Thanks.

Sorry.. I knew what I meant and assumed the folk telling me I was confused or did not know what I was talking about would as well.. Wrong..
But they know now so that's okay..
I'm off to bed, it's gone 4am..

[jmh2002]

Originally Posted by boatman61

Sorry.. I knew what I meant...

Ok

[Uricanejack]

Originally Posted by Dockhead

This is an absolutely crucially important point. None of this works if different vessels have different ideas about what phase of the crossing they are in. I think is one of the main sources of confusion among yachters, perhaps THE main source of confusion, and possibly the reason that so many just throw up their hands and try to follow some "rule of gross tonnage".


That part of Cockcroft about the four stages of a crossing is something everyone should read learn by heart:


Attachment 232302

Attachment 232303


Cockcroft & Lameijer, A Guide to the Collision Avoidance Rules, 6th ed. 2004, pp. 114-115



If you don't recognize what stage you're in, the the whole crossing will be a mess. The distance frames vary as Cockcroft says, but the ones he mentions are valid in 80% of cases at least in the waters I sail --


* No later than 5 to 8 miles out you are in risk of collision situation and stand on vessel is obligated to stand on


* by 2 to 3 miles out, stand on vessel is free to maneuver. Meaning, it would be very strange if give-way vessel has not maneuvered by 3 miles out and by then you should be prepared to take action.


The other concrete distance framework which everyone should understand is minimum CPA. It is normally one mile in open but crowded water, and may be two offshore. It is important for yachters to understand that commercial vessels will have standing orders requiring them to maintain minimum CPA with all vessels, normally one or two miles, so don't maneuver to get closer than that -- you cause them trouble and anyway its dangerous. A mile is a good minimum distance in any case -- less than a mile is close quarters and a whole different level of risk. The OP lacks these frameworks; a lot of this thread has been about that. In order to make and execute a decision and still maintain one mile CPA obviously you have to act long before one mile out.



This is all different in pilotage waters where ships are following fairways, channels, or obvious seaways. You can get a lot closer in such cases so long as you stay out of the fairways, channels, or obvious seaways, and the process is different.

Cockcroft trying to quantify something which was left intentionally unquantified.
Also just in my opinion a bit out of date. Not sure just when he first published this the 60s or The 70s probably the 60s.
Somebody might know better. It was certain in my copy from the late 70s.

Cockcroft clearly didn’t contemplate a 400m container ship doing 20 knots.
Encountering something similar.

They are in sight at 20+ miles.

By the same logic he wasn’t referring to a couple of 40 ft sail boats. Ither.

Why do the rules not give distances or times, the rules use vague terms like well clear, ample, readily apparent.
They are all subjective and context is important.
Cockcroft and other try to quantify these based on often quite old court cases.

So when I get up in the morning and go out in the boat, I’m not thinking in terms of stages.
It depends what boat I am going out on.

I would probably not have used the radio. At all. For a situation like this.
It’s no required, more importantly, I’d be concerned about miscommunication.

Contemplate this, Op reported the OOW response was “Ok carry on”

What did that mean? The OP took it to mean carry on and go astern, fortunately this appears to have been correct.

So even now unless I very confident about who I’m talking to I would be very reluctant to use the radio to make an agreement,
Particularly when things are going a bit pear shaped.

So when I start to get concerned, I’m going get little air horn out, open the package,
And I’m going to sound 5, futile or not, it’s why I bought the damn thing.
Hopefully I’m going to see a positive response.

I’ll a few minutes.
Then
I sound my 5 again,

No response I’m acting. Unilaterally, at this point I don’t know what the give way vessel is doing. I’ve taken matters into my own hands.
I’m going to resolve this safely by my self so my vessel stays safe.

Which is why I strongly recommend turn away.

When I turn away the other vessels actions or inactions are no longer a hazard to my.

If I’m give way I act at a reasonable time to keep well clear , making it readily apparent.
I’m happy, I’m in control of events, I get to decide the specifics, like
Or

I’m stand on,

This is where I think some folks get worked up, there not happy, they don’t feel like they are in control. They don’t get to decide the when and how

I’m still happy, because I am a still in control.

I still get to decide when I go from happy to not so happy,
Then after I’ve sounded my signal to express my concern doubt.

I am back in control,
I’m happy because I get to take action.

We probably have different personal thresholds because we are differ people with different boats.

I think some people particularly some of those who say just give way, are just don’t realize they are still in control of their vessel and can act when they feel it is required.

If you are going to use the radio, use it early. Be very clear you know who you are talking to. Use it a stage 2.

I won’t say I never use the radio when I sailing never is just to absolute.
I Rarely use the radio. I can’t when I last used it. I do listen. I suppose listening is using.

When I’m working, I use the radio, quite routinely. It can be very helpful. I’m participating in a VTS area. I communicate with VTS and other vessels quite regularly.
I often actualy know who I am talking to, even when I don’t know them personally, I know the vessel and the voice, sometimes just the voice.

My radio procedure sucks, it’s short, quick, to the point, not very clear sometimes,

Hey Cap, what your pleasure?

I’m easy.

Ok red to red.

Il haul over

Thanks Good voyage

I personally don’t like to ask for a departure from the rules.
But if I’m asked, I don’t usually argue, bother to argue.
Most guys will ask my pleasure, which is why I will often ask what the other guy wants.

Some times I’m stand on,
I call the give way.

If it’s not a big deal to me for one reason or anther.

I’ll ask what’s your pleasure.

Is he says green, fine at least I know,

If I care,

Hey Cap, looks like it will be kind of close, mind if I carry on.

What I really mean is hey buddy, we’re on a collision course, your give way, and it’s high time you did something about it.
But you catch more bees with honey,

I want to hear he plans to haul over.

Sometimes, it s something else.

A polite request to carry on. What the hell, in not going to argue. Most of the time.

If I really don’t like the response,

if you think it’s prudent.

Which really means I don’t think it is and I think he’s an idiot.

Sometimes it’s Il see you on 1 whistle.
Or I’ll see you on 2 whistles.

He from the East.

It’s the sound signals over VHF going to sound 1 short alter to starboard and see you red to red.
Or
2 altering to port for a Green to Green.

Meet or see you on the straight.

Meet you this side. Might add Red to Red or Green To Green.

Trying to sort any of this out with a ESL Deep Sea, forget about it.

Most of us Yokles have no clue about IMO standard international maritime vocabulary is

[Pelagic]

Uricanekack....
All that sounds like log towing lingo on the BC coast.

Very relaxed bunch of guys, but usually missing a few tips of their fingers[emoji16]

[HeinSdL]

Uricanejack, I am not sure if I follow you.

On the one hand you seem to know what you are talking about, advocating some punishment with a boot based on other people's statements & actions:

Originally Posted by Uricanejack

When the OOW adjust the auto pilot a few deg just to open the CPA a bit.
He deserves a boot 6 lace holes deep.
For the reasons Posted by DH.

But then this comes out a little bit later:

Originally Posted by Uricanejack

Hey Cap, what your pleasure?

I’m easy.

Ok red to red.

Il haul over

Thanks Good voyage

"Hey Cap, what your pleasure?" What is that? I am really not sure at all how I would respond to that and I would certainly not hail any commercial vessel with that kind of lousy opening.

Oh yes, and I will open up the CPA a bit when I am still at long range as the stand on vessel. If distance no longer permits I will indeed hold my course or change in a very significant way. But I am/was ASSUMING the PO had the possibility to do something about the situation when still at long range.

I picked up some useful wording from DH on this thread but otherwise it's just one big .

[Dockhead]

Originally Posted by Uricanejack

Cockcroft trying to quantify something which was left intentionally unquantified.
Also just in my opinion a bit out of date. Not sure just when he first published this the 60s or The 70s probably the 60s.
Somebody might know better. It was certain in my copy from the late 70s.

Cockcroft clearly didn’t contemplate a 400m container ship doing 20 knots.
Encountering something similar.

They are in sight at 20+ miles.

By the same logic he wasn’t referring to a couple of 40 ft sail boats. Ither.

Why do the rules not give distances or times, the rules use vague terms like well clear, ample, readily apparent.
They are all subjective and context is important.
Cockcroft and other try to quantify these based on often quite old court cases.

So when I get up in the morning and go out in the boat, I’m not thinking in terms of stages.
It depends what boat I am going out on.

I would probably not have used the radio. At all. For a situation like this.
It’s no required, more importantly, I’d be concerned about miscommunication.

Contemplate this, Op reported the OOW response was “Ok carry on”

What did that mean? The OP took it to mean carry on and go astern, fortunately this appears to have been correct.

So even now unless I very confident about who I’m talking to I would be very reluctant to use the radio to make an agreement,
Particularly when things are going a bit pear shaped.

So when I start to get concerned, I’m going get little air horn out, open the package,
And I’m going to sound 5, futile or not, it’s why I bought the damn thing.
Hopefully I’m going to see a positive response.

I’ll a few minutes.
Then
I sound my 5 again,

No response I’m acting. Unilaterally, at this point I don’t know what the give way vessel is doing. I’ve taken matters into my own hands.
I’m going to resolve this safely by my self so my vessel stays safe.

Which is why I strongly recommend turn away.

When I turn away the other vessels actions or inactions are no longer a hazard to my.

If I’m give way I act at a reasonable time to keep well clear , making it readily apparent.
I’m happy, I’m in control of events, I get to decide the specifics, like
Or

I’m stand on,

This is where I think some folks get worked up, there not happy, they don’t feel like they are in control. They don’t get to decide the when and how

I’m still happy, because I am a still in control.

I still get to decide when I go from happy to not so happy,
Then after I’ve sounded my signal to express my concern doubt.

I am back in control,
I’m happy because I get to take action.

We probably have different personal thresholds because we are differ people with different boats.

I think some people particularly some of those who say just give way, are just don’t realize they are still in control of their vessel and can act when they feel it is required.

If you are going to use the radio, use it early. Be very clear you know who you are talking to. Use it a stage 2.

I won’t say I never use the radio when I sailing never is just to absolute.
I Rarely use the radio. I can’t when I last used it. I do listen. I suppose listening is using.

When I’m working, I use the radio, quite routinely. It can be very helpful. I’m participating in a VTS area. I communicate with VTS and other vessels quite regularly.
I often actualy know who I am talking to, even when I don’t know them personally, I know the vessel and the voice, sometimes just the voice.

My radio procedure sucks, it’s short, quick, to the point, not very clear sometimes,

Hey Cap, what your pleasure?

I’m easy.

Ok red to red.

Il haul over

Thanks Good voyage

I personally don’t like to ask for a departure from the rules.
But if I’m asked, I don’t usually argue, bother to argue.
Most guys will ask my pleasure, which is why I will often ask what the other guy wants.

Some times I’m stand on,
I call the give way.

If it’s not a big deal to me for one reason or anther.

I’ll ask what’s your pleasure.

Is he says green, fine at least I know,

If I care,

Hey Cap, looks like it will be kind of close, mind if I carry on.

What I really mean is hey buddy, we’re on a collision course, your give way, and it’s high time you did something about it.
But you catch more bees with honey,

I want to hear he plans to haul over.

Sometimes, it s something else.

A polite request to carry on. What the hell, in not going to argue. Most of the time.

If I really don’t like the response,

if you think it’s prudent.

Which really means I don’t think it is and I think he’s an idiot.

Sometimes it’s Il see you on 1 whistle.
Or I’ll see you on 2 whistles.

He from the East.

It’s the sound signals over VHF going to sound 1 short alter to starboard and see you red to red.
Or
2 altering to port for a Green to Green.

Meet or see you on the straight.

Meet you this side. Might add Red to Red or Green To Green.

Trying to sort any of this out with a ESL Deep Sea, forget about it.

Most of us Yokles have no clue about IMO standard international maritime vocabulary is

Well, that's consummately professional. Very useful for us yachters that you posted all this. Guys note:


1. Healthy reluctance to use the radio, and for God's sake not at a late stage of a crossing.


2. Healthy reluctance to ask for a deviation from the Rules.


3. Cheerful, collegial acquiescence in requests of others.


4. Not bothered by those failing to give way, and great courtesy in asking if they will.


5. Default attitude is "what's your pleasure"



6. Use of 5 short as a primary communication tool (something unfortunately we don't have).


We should all be more like this. Especially -- "what's your pleasure".





As to distances for the different stages: yes, of course, the Rules specifically say that they are not fixed. Yet, you have to get in synch with other vessels. So I think it's useful to perceive and understand in what time and distance frames other vessels are acting.


And to know the limits.


And you said yourself that as stand-on you will already be in serious doubt by 3 miles out if the give-way vessel hasn't maneuvered. I think that distance frame -- as a minimum -- holds over a pretty wide variety of speeds and waters, so long as you are not in pilotage waters. Because to keep a 1 mile minimum CPA -- another very widely used parameter -- you will need to take fairly bold action by no more than about 2 miles out.



That's my usual practice, and I am in good synch with the ships in the waters I sail in. Far offshore these distances are longer, and minimum CPA might be 2 miles. But with the typical traffic in the English Channel, this works well.



Another trick to determine whether you have been seen by the give-way vessel and can carry on your course is to watch the CPA at about 10 miles out. In the English Channel, if there are no complications from other traffic, the give way vessel very often adjusts his course right at 10 miles out, to exactly 1 mile CPA. When you see that happen then you know he's dealing with the crossing, so carry on and watch closely as the crossing develops.


The OP was "in extremis" -- 5 cables out, with 100 seconds or whatever to collision, so no margin for error whatsoever, and he was on the radio. If he and the ship had maneuvered towards each other, he wouldn't have even been able to perceive the changed situation until it was too late to get out of the way. That's why UJ recommended tacking away. That's not the kind of maneuvering you want to do -- when it's all done in time, you don't need desperate maneuvers like that. If you are really in control of the crossing, then it is all set up by 3 miles out and all you have to do is watch carefully that nothing changes, and then pass smoothly. If something does go wrong, you have time to correct it. If you are stand-on and the give-way vessel doesn't maneuver, then at least by two miles out you want to have it sorted. If for some reason you feel you need radio communications, do it early, as UJ says. Do it while you still have time not to be concentrating on the developing situation, and while you have time to take a reasonable amount of time to be sure you have agreed, and for whatever you have agreed on to be implemented. Being on the radio 5 cables and 100 seconds from a collision can easily get you killed.

[boatman61]

Originally Posted by jmh2002

Ok

Phew.. I'm sooooo relieved..

[jtsailjt]

I think uricanejack has got it mostly right regarding distances but as long as he’s saying things like “what’s your pleasure” and “I’m easy” I’m afraid “ consummate professional” doesn’t quite come to mind. But it makes it easy to understand his perception that VHF communications can be very confusing! IF engine noise isn’t an issue and there’s no static or distortion on the VHF and you know you’re speaking to a buddy of yours or at least someone with a similar background, then he will probably understand that by saying “I’m easy” you really mean that you are willing to alter your course/speed or allow the other vessel to. But if the skipper of the other vessel is from a different culture or there’s a bit of static or someone else aboard his vessel speaks when you are saying “I’m easy” you are quite likely to have not communicated effectively or at all. Those of us who grew up speaking English as our first language will usually understand when someone uses slang terminology but for those who speak multiple languages it’s nearly impossible for them to understand anything other than the literal translation of what they hear. As has been noted, communicating over the VHF radio is fraught with enough obstacles such as background noise, hissing, popping, differing accents, etc. so in order to minimize confusion I think it’s pretty important to be clear about who you are addressing, who you are, and exactly what the subject of your transmission is (concern about crossing geometry and who will alter course in this case) by trying to use unambiguous and clear wording. By the time you feel the need to talk on the radio and manage to get the other vessels attention in order to resolve a crossing situation, while it’s not yet an emergency, you really don’t want to take a chance on confusing the other skipper as to your intentions and then spend the next 5 minutes trying to sort out what you/he really meant and re-adjusting the course adjustment you or he made as a result. It’s important to speak very clearly and try to choose words that can’t possibly be misinterpreted. It’s perfectly ok to sound like a nerd with no personality. The important thing is to communicate clearly and be safe.

[boatman61]

Originally Posted by jtsailjt

I think uricanejack has got it mostly right regarding distances but as long as he’s saying things like “what’s your pleasure” and “I’m easy” I’m afraid “ consummate professional” doesn’t quite come to mind. But it makes it easy to understand his perception that VHF communications can be very confusing! IF engine noise isn’t an issue and there’s no static or distortion on the VHF and you know you’re speaking to a buddy of yours or at least someone with a similar background, then he will probably understand that by saying “I’m easy” you really mean that you are willing to alter your course/speed or allow the other vessel to. But if the skipper of the other vessel is from a different culture or there’s a bit of static or someone else aboard his vessel speaks when you are saying “I’m easy” you are quite likely to have not communicated effectively or at all. Those of us who grew up speaking English as our first language will usually understand when someone uses slang terminology but for those who speak multiple languages it’s nearly impossible for them to understand anything other than the literal translation of what they hear. As has been noted, communicating over the VHF radio is fraught with enough obstacles such as background noise, hissing, popping, differing accents, etc. so in order to minimize confusion I think it’s pretty important to be clear about who you are addressing, who you are, and exactly what the subject of your transmission is (concern about crossing geometry and who will alter course in this case) by trying to use unambiguous and clear wording. By the time you feel the need to talk on the radio and manage to get the other vessels attention in order to resolve a crossing situation, while it’s not yet an emergency, you really don’t want to take a chance on confusing the other skipper as to your intentions and then spend the next 5 minutes trying to sort out what you/he really meant and re-adjusting the course adjustment you or he made as a result. It’s important to speak very clearly and try to choose words that can’t possibly be misinterpreted. It’s perfectly ok to sound like a nerd with no personality. The important thing is to communicate clearly and be safe.

I would like to see him pass a VHF Exam in the UK talking like that..

[HeinSdL]

Originally Posted by boatman61

I would like to see him pass a VHF Exam in the UK talking like that..

Quite. As I found out to my benefit when doing mine, in the UK. It is OK, and indeed necessary, to be somewhat of a nerd on the VHF.

And so comes the irony. On the one hand you should be absolutely clear with your intentions when changing course and/or speed, but when it comes to the VHF some slang in use amongst buddies on some US waterway is just fine. One should eat one's own cooking, is it not the saying?

[boatman61]

Originally Posted by HeinSdL

Quite. As I found out to my benefit when doing mine, in the UK. It is OK, and indeed necessary, to be somewhat of a nerd on the VHF.

And so comes the irony. On the one hand you should be absolutely clear with your intentions when changing course and/or speed, but when it comes to the VHF some slang in use amongst buddies on some US waterway is just fine. One should eat one's own cooking, is it not the saying?

True.. and with the massive increase of Asian skippers and crews in International waters, following International VHF procedure is vital in heavy commercial traffic situations.
Ch 16 is a much abused channel with folk holding yacht to yacht conversations and sad to say even some ships..
The first thing I say once contact is established is "Thank you, switch to Ch 6.." and take it from there.. or the ship will respond by naming me and say "Going to Ch 6.."
If we're going to just holler from a rule book rather than analyzing situations let's be consistent..

[Pelagic]

Originally Posted by Dockhead

This is an absolutely crucially important point. None of this works if different vessels have different ideas about what phase of the crossing they are in. I think is one of the main sources of confusion among yachters, perhaps THE main source of confusion, and possibly the reason that so many just throw up their hands and try to follow some "rule of gross tonnage".


That part of Cockcroft about the four stages of a crossing is something everyone should read learn by heart:


Attachment 232302

Attachment 232303


Cockcroft & Lameijer, A Guide to the Collision Avoidance Rules, 6th ed. 2004, pp. 114-115



If you don't recognize what stage you're in, the the whole crossing will be a mess. The distance frames vary as Cockcroft says, but the ones he mentions are valid in 80% of cases at least in the waters I sail --


* No later than 5 to 8 miles out you are in risk of collision situation and stand on vessel is obligated to stand on


* by 2 to 3 miles out, stand on vessel is free to maneuver. Meaning, it would be very strange if give-way vessel has not maneuvered by 3 miles out and by then you should be prepared to take action.


The other concrete distance framework which everyone should understand is minimum CPA. It is normally one mile in open but crowded water, and may be two offshore. It is important for yachters to understand that commercial vessels will have standing orders requiring them to maintain minimum CPA with all vessels, normally one or two miles, so don't maneuver to get closer than that -- you cause them trouble and anyway its dangerous. A mile is a good minimum distance in any case -- less than a mile is close quarters and a whole different level of risk. The OP lacks these frameworks; a lot of this thread has been about that. In order to make and execute a decision and still maintain one mile CPA obviously you have to act long before one mile out.



This is all different in pilotage waters where ships are following fairways, channels, or obvious seaways. You can get a lot closer in such cases so long as you stay out of the fairways, channels, or obvious seaways, and the process is different.

Good sumary DH

One tip if dealing with a large number of targets as in the merging aproaches to Singapore from the north is to organize priorities based on Time of CPA, (TCPA).

Sometimes you will want to make minor adjustments early as these vessels converge into a dense area before a seperaton zones begins

If your ARPA Radar is fitted with a Trial Mode... then use that to TEST a Course or Speed change, rather than actually changing.

It creates less confusion with the other watchkeepers.

Another tip if in very busy multilateral traffic, is to switch to True Motion as you can immediately see course changes as ships take evasive actions with each other.

I still keep the Bearings Relative but the birds eye true motion with extended headings and tracks, gives you a very good picture at a glance of intentions and history in real time.

[Uricanejack]

Originally Posted by boatman61

I would like to see him pass a VHF Exam in the UK talking like that..

Ha ha.

I did once upon a time long long ago.

Two peoples separated by a common language. According to Winston.

[Uricanejack]

Originally Posted by HeinSdL

Uricanejack, I am not sure if I follow you.

On the one hand you seem to know what you are talking about, advocating some punishment with a boot based on other people's statements & actions:



But then this comes out a little bit later:



"Hey Cap, what your pleasure?" What is that? I am really not sure at all how I would respond to that and I would certainly not hail any commercial vessel with that kind of lousy opening.

Oh yes, and I will open up the CPA a bit when I am still at long range as the stand on vessel. If distance no longer permits I will indeed hold my course or change in a very significant way. But I am/was ASSUMING the PO had the possibility to do something about the situation when still at long range.

I picked up some useful wording from DH on this thread but otherwise it's just one big .

Ok

10 miles plus suit yourself, do what you want . Like DH said it’s a long ways away and the process hasn’t started yet.

In to days world an actual boot would lead to all sorts of paperwork, probably followed by a complaint to a human rights tribunal at The Hague.
So just a figure of speech, intended to be humour

Point being, I would be less than happy with an OOW who makes small alterations for collision avoidance. He or she would be advised why It’s not recommended and pleas don’t do it again.
Make your alteration obvious to the other vessel so your intentions are clear.

The rest is also intended to be a bit of a humorous illustration of VHF communication, it is actually literal real VHF use.

Call if you like, I’m on the VTS channel , I will answer, I will most likely suggest a solution which is in line with the rules.

So my preference will probably be. I will alter course and pass safety astern of a sailboat.

Which is what I would already be planning to do,

On a few occasions, I might even call one, myself, if I can ID if it’s got AIS.
Usually, to confirm I see it and will be taking action, just so they don’t get concerned, it’s usually some where I be passing quite close.

I occasionally will call a small craft or sailing vessel and ask which side they would prefer me to pass them on.

You can translate this to, there are two side to this channel please pick one.

10 4 buddy, have a good one

[Lodesman]

Originally Posted by Uricanejack

Cockcroft trying to quantify something which was left intentionally unquantified.
Also just in my opinion a bit out of date. Not sure just when he first published this the 60s or The 70s probably the 60s.
Somebody might know better. It was certain in my copy from the late 70s.

Cockcroft clearly didn’t contemplate a 400m container ship doing 20 knots.
Encountering something similar.

First published in 1965, I can only assume it was then a guide to the 1960 rules; and the 1976 second edition changed to reflect the 1972 conventions. I'm pulling this from my 5th ed. which includes the '87 and '93 amendments. It references cases (collisions) from the mid-90s and in the Watchkeeper's notes at the back they discuss the manoeuvrability of vessels up to 45 kts. I believe newer editions have inclusions for WIGs and high-speed vessels. All to say the mentioned attempt to quantify the unquantified, is still a useful tool today. Obviously at higher speeds one extends the ranges a bit, and at lower speeds can bring them in, but the concept remains valid.