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Old 21-06-2015, 04:43   #91
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Re: Container Ship and Saliboats

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Originally Posted by Dockhead View Post
I certainly agree with you about holding course and speed when it's required - collision avoidance can't work if someone doesn't "hold still". But why do you say this? When I learned to sail in the 70s, in racing dinghies which didn't carry HBCs, this was taught as the most basic collision avoidance technique. Unless the ship is turning towards you, it's guaranteed to work. It's not going to be the most efficient way out, but it's dead simple to execute. Why is it "sophomoric"? Am I missing something?
Let's consider Mike's own example - sailboat at 6 kts, and containership at 23 kts. For a collision to even be possible the sailboat has to be anywhere from dead ahead of the ship to about 15 either side of that. As I've said in a previous thread, the stern of the ship isn't even visible from the boat's perspective. In the best case scenario, where the courses are perpendicular, at 4 miles range the boat is only 1 mile from the path of the ship. If the scenario is closer to being end-on or overtaking, the distance from the ship's path is much closer. Pointing at the stern further decreases that range, so while they might not collide, it could certainly be a very close pass.

I note you've provided a caveat:
Quote:
Unless the ship is turning towards you, it's guaranteed to work.
So let's consider that there are actual professionals on the bridge of the ship, who don't wear thick glasses. Rule 18 only says they have to stay out of the way of sailboats, not how to do it. We've heard how long it takes to stop a large ship, so let's assume slowing down is not practical, so a turn to either port or stbd is possible. The most likely would be a turn to go astern of the sailboat - that "point at the stern" trick works both ways. Assuming the 2 vessels turn at roughly the same time, they'll end up 3 miles apart, pointing at each other and closing at a rate of 30 kts. That should be exciting.
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Old 21-06-2015, 04:55   #92
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Re: Container Ship and Saliboats

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Originally Posted by Lodesman View Post
Let's consider Mike's own example - sailboat at 6 kts, and containership at 23 kts. For a collision to even be possible the sailboat has to be anywhere from dead ahead of the ship to about 15 either side of that. As I've said in a previous thread, the stern of the ship isn't even visible from the boat's perspective. In the best case scenario, where the courses are perpendicular, at 4 miles range the boat is only 1 mile from the path of the ship. If the scenario is closer to being end-on or overtaking, the distance from the ship's path is much closer. Pointing at the stern further decreases that range, so while they might not collide, it could certainly be a very close pass.

I note you've provided a caveat:
So let's consider that there are actual professionals on the bridge of the ship, who don't wear thick glasses. Rule 18 only says they have to stay out of the way of sailboats, not how to do it. We've heard how long it takes to stop a large ship, so let's assume slowing down is not practical, so a turn to either port or stbd is possible. The most likely would be a turn to go astern of the sailboat - that "point at the stern" trick works both ways. Assuming the 2 vessels turn at roughly the same time, they'll end up 3 miles apart, pointing at each other and closing at a rate of 30 kts. That should be exciting.
OK, fair enough, but you shouldn't be doing any altering at all, during the phase when you are supposed to be standing on. Your post just underlines once again how important it is to obey the requirement to stand on, and why it's important. It's a bit like two people on a collision course on a busy sidewalk. They may easily avoid right into each other, if one of them doesn't hold still.


And obviously you can't do any stern-pointing if you can't even see the stern of the ship.


But if you are allowed to maneuver, and if you can see the ship's stern, and if the ship is holding its own course and speed, and if for some reason you can't or don't have time to plot an exact maneuver to give a certain CPA, I think this is a great maneuver. It doesn't require any thought or analysis or the use of any equipment, and sometimes in a stressful situation you need something which can solve the situation without increasing the workload. Or do you disagree?
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Old 21-06-2015, 05:52   #93
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Re: Container Ship and Saliboats

It's a perfectly fine manoeuvre - provided the two vessels are more closely matched in speed, or you're in the faster vessel. Perfectly fine if you're the give way vessel. Not really the best advice for a 17(a)(ii) action.
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Old 21-06-2015, 06:06   #94
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Re: Container Ship and Saliboats

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Originally Posted by captain58sailin View Post
I wish I had a nickel for every time someone tried to sail between me and my barge.
I wonder how anyone could be in a position to sail between you and your barge? Shouldn't you have avoided the sail boats?
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Old 21-06-2015, 06:55   #95
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Re: Container Ship and Saliboats

In the case being discussed, where there is a large disparity in size and speed between two vessels, while it's certainly simple to remember and execute, it seems to me that pointing at the stern of the faster vessel has very limited usefulness. If the sailboat is traveling at 6 knots and the larger vessel is traveling at 23, then it would be impossible for a collision to occur unless the sailboat is in about a 15-20 degree cone off the ships bow, in which case, the stern of the ship won't be visible to him. If you can see the stern of a much faster moving vessel, then that means you are beside him and couldn't hit him if you tried to. Also, as has been pointed out, if he's towing something and you pointed at his stern, you've probably put yourself on a collision course with his tow or the towing cable. I do see where stern pointing could be useful in cases where the two vessels are more evenly matched in speed.

One thing that I find interesting in this discussion is determining when the colregs apply, which is defined in them as "when a risk of collision exists." For Dockhead, watching his AIS and radar and analyzing what he sees while 6 to 10 miles away, that may be prior to the other vessel even being aware that he's out there. The other extreme are those who may not sense that a risk of collision exists until they see the other vessel emerge from the fog 1/4 mile away. So both captains know and intend to follow the colregs (once they determine that a risk of collision exists) but their actions to attempt to avoid collision may be vastly different during that period of time between when one detects the potential collision while many miles away on his AIS and the other detects the potential collision by noticing that something seems to have just blocked out the sun. Then we have Captnmike saying that he can't maneuver anyway even though he has the equipment and manpower aboard to see/detect you early, so you better get out of his way if you know what's good for you. There seems to be a lot of gray area in this discussion. I understand the need to be predictable to avoid the situation we've all experienced where two people walking down a hallway both try to avoid each other and as a result end up walking into each other, but at the same time, according to the colregs it's always everyone's responsibility to do whatever they deem necessary to avoid colliding, whether they be the stand on or burdened vessel, and this becomes especially important when the other vessel hasn't even detected you yet or is unable to maneuver to avoid you, which are both conditions that you may not be in a position to be aware of. Lots of room for judgement here! The bottom line seems to be, be aware of the colregs and attempt to follow their guidance, but don't assume the other guy always can/will, and whether he does or not, YOU always still have to do whatever it takes to avoid a collision.
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Old 21-06-2015, 07:03   #96
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Re: Container Ship and Saliboats

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Originally Posted by Lodesman View Post
I wonder how anyone could be in a position to sail between you and your barge? Shouldn't you have avoided the sail boats?
I tried to do that once and it certainly wasn't the towing vessels fault. At night in the Bahamas sailing with my father who was seasick so I was at the helm constantly, I saw a ship on radar and then saw his lights visually and as fatigued as I was, I was so focused on avoiding him by passing just behind him that I stopped looking at my radar and didn't notice the barge he was towing until he informed me of it on Ch 16. He wasn't in a position where he could maneuver his barge to avoid me, but he did possibly save my life by sharing his situation awareness with me over the radio so I could turn to avoid running into either his cable or his barge.
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Old 21-06-2015, 07:13   #97
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Re: Container Ship and Saliboats

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Originally Posted by jtsailjt View Post
In the case being discussed, where there is a large disparity in size and speed between two vessels, while it's certainly simple to remember and execute, it seems to me that pointing at the stern of the faster vessel has very limited usefulness. If the sailboat is traveling at 6 knots and the larger vessel is traveling at 23, then it would be impossible for a collision to occur unless the sailboat is in about a 15-20 degree cone off the ships bow, in which case, the stern of the ship won't be visible to him. If you can see the stern of a much faster moving vessel, then that means you are beside him and couldn't hit him if you tried to. .
This is often true, and very important -- in my experience, recreational sailors are often entirely clueless about the implications of the difference in speed. For example -- one of my pet peeves -- that they assume that they are always "much more maneuverable" than large vessels.

Which is why in the situation you describe, with nearly 4:1 difference in speed, not just stern-pointing is useless, but just about any maneuver you can make on the slow vessel is useless.

But few ships you encounter are travelling at 23 knots -- 90% of ships in the English channel are making something in the teens. There are plenty of collision courses between yachts and ships in real life where the sailor can see the ship's stern.
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Old 21-06-2015, 09:43   #98
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Re: Container Ship and Saliboats

Many people on this thread are talking about "if you are six miles off and a risk of collision exists" or similar. I'm in a small sailboat, a Cal 39, and unless the other vessel and I are on directly reciprocal courses, or close to that, six miles is just to great to determine that a realistic "risk of collission" exists. It's close enough for me to watch, but not close enough for me to determine if a course and/or speed change will be required, and if so what the required change should be. Yes, I know that commercial ships like to have a CPA of one mile, and that's fine in the open ocean. But that's because it takes them nearly a mile to make a significant change of course and/or speed. I, on the other hand, can significantly change course and/or speed in less than 100 FEET, and sea and/or weather conditions will probably do that for me before I can get half that distance. So whether or not I consider a CBDD as indicating a significant RISK of collission greatly depends upon the rate of the DD. I make the changes when I think that the skipper of the other vessel MIGHT consider a CBDD as an indication that a risk of collision (ROC) exists (as that is always at a greater distance than what I'd consider necessary).
As for a ROC between me and a commercial vessel I operate on the assumption that I'm the one to do the changes since I can do them so easily and quickly (and they might not even know I exist). I am responsible for the lives of my passengers (and me too) and the life of my boat. I do what is necessary to prolong them. I try to make the change in course and/or speed early enough and of sufficient magnitude for the other skipper to recognize the fact. (This MAY not be the way I act when the other vessel is one of my competitors in a race at the time - and somewhat modified if it's another sailboat that's not racing while I am).
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Old 21-06-2015, 09:54   #99
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Re: Container Ship and Saliboats

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Originally Posted by secrabtree View Post
Many people on this thread are talking about "if you are six miles off and a risk of collision exists" or similar. I'm in a small sailboat, a Cal 39, and unless the other vessel and I are on directly reciprocal courses, or close to that, six miles is just to great to determine that a realistic "risk of collission" exists. It's close enough for me to watch, but not close enough for me to determine if a course and/or speed change will be required, and if so what the required change should be. Yes, I know that commercial ships like to have a CPA of one mile, and that's fine in the open ocean. But that's because it takes them nearly a mile to make a significant change of course and/or speed. I, on the other hand, can significantly change course and/or speed in less than 100 FEET, and sea and/or weather conditions will probably do that for me before I can get half that distance. So whether or not I consider a CBDD as indicating a significant RISK of collission greatly depends upon the rate of the DD. I make the changes when I think that the skipper of the other vessel MIGHT consider a CBDD as an indication that a risk of collision (ROC) exists (as that is always at a greater distance than what I'd consider necessary).
As for a ROC between me and a commercial vessel I operate on the assumption that I'm the one to do the changes since I can do them so easily and quickly (and they might not even know I exist). I am responsible for the lives of my passengers (and me too) and the life of my boat. I do what is necessary to prolong them. I try to make the change in course and/or speed early enough and of sufficient magnitude for the other skipper to recognize the fact. (This MAY not be the way I act when the other vessel is one of my competitors in a race at the time - and somewhat modified if it's another sailboat that's not racing while I am).
A couple of things I would suggest you consider:

1. You CAN determine a collision from six miles off -- don't you have a hand bearing compass? DETECTION of a potential collision is just as important as any of the other aspects of collision avoidance. You should be aware of vessels from at least 10 miles off and if there is any doubt about whether there is a collision course, you need to get to work figuring it out and monitoring the situation. "IF there is any doubt" means the ship is not moving against a stanchion or otherwise showing a sign of obvious changing bearing. You really need that much time -- from 10 miles off -- to do effective collision avoidance in open water. AIS of course makes this trivial, but a HBC is effective enough.

2. You can change directions quickly, but what does it take to open up your CPA and turn a potential collision situation into a safe crossing? I'll tell you -- it's SPEED. In a small boat moving at 5 or 6 knots, you will be helpless to do much about a collision with a ship travelling at three times your speed, once the ship is three or four miles away. The path of the ship bearing down on you can be projected as a cone depending on the degree of uncertainty of his path. The less precise methods you have to determine CPA and change of bearing, the wider that cone will be. Too wide in many cases for you to get out of it travelling at 5 or 6 knots.


I would suggest a serious review of collision avoidance techniques.
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Old 21-06-2015, 13:56   #100
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Re: Container Ship and Saliboats

[QUOTE=Dockhead;1852694]A couple of things I would suggest you consider:

1. You CAN determine a collision from six miles off -- don't you have a hand bearing compass? QUOTE
My response - Yes, I can determine if, under existing concitions, the existing courses and speeds present a collision course situation. What a hand bearing compass will not tell me is if the conditions will remain exactly the same. I must make a decision of how much time exists until the potential collission and how likely is it that the conditions during that time will maintain that risk of collision. That time will depend upon the type and size of the other vessel, my boat, weather conditions, etc.
QUOTE 2. You can change directions quickly, but what does it take to open up your CPA and turn a potential collision situation into a safe crossing? I'll tell you -- it's SPEED. In a small boat moving at 5 or 6 knots, you will be helpless to do much about a collision with a ship travelling at three times your speed, once the ship is three or four miles away. QUOTE
My response - That is only true if that other ship is attempting to cause a collision. I don't think that a large commercial freighter would make such an attempt, either intentionally or accidentally.
QUOTE The path of the ship bearing down on you can be projected as a cone depending on the degree of uncertainty of his path. The less precise methods you have to determine CPA and change of bearing, the wider that cone will be. Too wide in many cases for you to get out of it travelling at 5 or 6 knots. QUOTE
My response - One instance, only one, but the most dangerous. We were entering San Diego one moonless night. My wife was on the helm. She wondered why San Diego had a whole lot of lights ashore and in the hills all over but straight ahead. She made that wonder allowd and I came on deck and looked up to see a red light and a green light. We were on a reciprocal course with a LARGE vessel, and VERY close, close enough that we couldn't see the bridge except for the extreme outboard end of it. Of course we got 5 blasts of the horn at the exact time that I emerged from the cabin. The distance was less than a mile, probably less than a hundred yards. And we were DIRECTLY in front of the ship. We were probably going three knots towards the bow of a ship probabl going more than six knots (probably more than 10) on a reciprocal course. We EASILY moved out of his way.
Yes, the CPA was less than a mile. The channel itself was only a few hundred yards wide.
Another time, many years ago near San Miguel Island in the Santa Barbara Channel, the helmsman saw a one. We were under sail with a Monitor windvain doing the steering. I was called out of the cabin, saw the red light and green light at an elevation of about 45. I lunged at the Monitor and, with the limited mobility of the not disconnected Monitor, got out of the way (though I did see the rust on the welds on the ship).

QUOTEI would suggest a serious review of collision avoidance techniques. QUOTE
My response - Maybe I have become too complacent from having sailed and raced in the crowded shipping conditions of San Francisco Bay, the Oakland Estuary, the Sacramento Deep Water Channel, the Stocton Shipping Channel, Puget Sound, Los Angeles Harbor, and San Diego, and, of course less busy harbors, too. ALL of these locations provided situations with large commercial vessels that were MUCH more challenging than any I have encountered in my dozen Hawaii passages or my uncounted coastal passages between Cabo Corientes and Cape Flattery. I realize that I have not had the quantity of open ocean experience that you have. But the open ocean experience that I have had has led me to believe that navigation, including collision avoidance technique, is less challenging in the open ocean than it is coastally. And coastal is less challenging than inland.
And I started making ocean passages to and from Hawaii using celestial, before GPS was affordable.
Those trips taught me not to rely on merchant vessels to see me, and that it was incumbant on me to avoid them. And I've not been run over, or even had a close encounter, while in the open ocean.
Inshore, close encounters are a fact of life. CPAs of a mile aren't usually possible, and where possible nobody seems to think that such a one mile CPA is even to be desired.
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Old 21-06-2015, 16:53   #101
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Re: Container Ship and Saliboats

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I tried to do that once and it certainly wasn't the towing vessels fault. At night in the Bahamas sailing with my father who was seasick so I was at the helm constantly, I saw a ship on radar and then saw his lights visually and as fatigued as I was, I was so focused on avoiding him by passing just behind him that I stopped looking at my radar and didn't notice the barge he was towing until he informed me of it on Ch 16. He wasn't in a position where he could maneuver his barge to avoid me, but he did possibly save my life by sharing his situation awareness with me over the radio so I could turn to avoid running into either his cable or his barge.
Don't have all the details, but this sounds like a potential tragedy that could have been avoided if everyone followed the rules. Generally in open ocean a tug and tow have to keep out of the way of a sailboat. If you had stood on and he made the sensible alteration to pass astern of you, there would have been no way for you to cut between him and his tow - everybody's happy; no death for you, less paperwork for him.
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Old 21-06-2015, 17:11   #102
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Re: Container Ship and Saliboats

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Don't have all the details, but this sounds like a potential tragedy that could have been avoided if everyone followed the rules. Generally in open ocean a tug and tow have to keep out of the way of a sailboat. If you had stood on and he made the sensible alteration to pass astern of you, there would have been no way for you to cut between him and his tow - everybody's happy; no death for you, less paperwork for him.
Never seen that happen (tugs with tows to maneuver around pleasure boats) in the Bay Area (admittedly not the open sea). Here I'm to port and have no claim so am turning to starboard to pass behind the barge:

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Old 21-06-2015, 18:05   #103
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Re: Container Ship and Saliboats

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Never seen that happen (tugs with tows to maneuver around pleasure boats) in the Bay Area (admittedly not the open sea).
I'm not familiar with your Bay - are there special local rules? I imagine most tugs follow the traffic lanes, so have the "privileges" that affords. No ball-diamond-ball on the tug in your pic, so he's just a power-driven vessel as far as the rules see him - he should act accordingly.
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Old 21-06-2015, 18:43   #104
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Re: Container Ship and Saliboats

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Tacking away is easy-peasy. Sometimes, gybeing away is difficult to effect in a timely fashion. Not that it shouldn't be done, --we're more maneuverable than they--, just that at zero dark thiry, it will not happen as fast as on a racing boat with full crew.

Ann
That should not happen when you have full crew @ watch @ zero dark thirty if it does the crew is asleep! Single handing, maybe, full crew, no way! Also that type of boat (racing boat) should have alarms setup to notify you of a collision about to occur! make your course adjustment sooner than as needed! Come on dude! Let's be real about this! Their is no reason for the type of scenario you just suggested!
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Old 21-06-2015, 18:46   #105
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Re: Container Ship and Saliboats

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I'm not familiar with your Bay - are there special local rules? I imagine most tugs follow the traffic lanes, so have the "privileges" that affords. No ball-diamond-ball on the tug in your pic, so he's just a power-driven vessel as far as the rules see him - he should act accordingly.
By the time one recognizes a day sign, it may be too late.

Most all the SF estuary contains sea lanes and limited waters although most tugs and their barges can navigate out of the ship channels. But to be realistic/practical, commercial vessels rule the waters. Regardless, we are polite and watch out for each other.

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