Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 12-01-2016, 10:27   #91
Moderator
 
nigel1's Avatar

Cruisers Forum Supporter

Join Date: Oct 2009
Location: Manchester, UK
Boat: Beneteau 473
Posts: 5,194
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by Muckle Flugga View Post
Good to know, though I don't usually try to hail them in SE Asian waters anymore, if local vessels. I have tried few times to do this with Indonesian vessels and drawn a blank. Certainly would do elsewhere, although find it far less frequent in the Atlantic or Pacific regions.

Having had an Indonesian cargo ship run over my tow wire in the Singapore Straits, despite being called by myself and VTIS, use of searchlight's etc, I'm not surprised.
__________________

__________________
Nigel
Beneteau 473
Manchester, UK
nigel1 is online now   Reply With Quote
Old 12-01-2016, 11:29   #92
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 5,765
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by Dockhead View Post
Well, this contradicts the premise of your previous post, which was that "even if I'm the stand on vessel". If you're the stand-on vessel, then a risk of collision already exists, and the procedure you described is very bad, in fact, a museum of typical collision avoidance mistakes made by recreational sailors, and the reason why commercial mariners refer to us as "WAFIs" -- Wind Assisted F**** Idiots.
...
You are correct I expressed myself badly. What I mean is that if I pursued on that course for several more miles a risk of collision would exist and on that situation I would be the stand-on vessel.

I avoid the situation of collision risk before it is even a considered a possibility altering my course, therefore strictly speaking I am not a stand-on vessel since the COLREGS in what regards risk of collision or action to avoid collision are not applicable at that distance.

Regarding the distance a small sailing boat should be considered a stand on vessel I have some doubts. Sailboats due to the way they sail (with the wind) have many times to alter course due to wind variation or due sailing upwind or downwind.

Don't seem to me logical to me that a small sailingboat stand on distance regarding the risk of collision should be the same regarding a 100 000T bulk carrier and I would like to hear Nigel (and other Merchant ship captains ) about that:

At what distance, regarding a course with a CPA close enough to raise concerns about a possibility of collision, they assume a small sailing boat is the stand on vessel (meaning that they consider the sailboat will not alter their course) and act accordingly altering the ship's course. What is the normal practice?
__________________

Polux is offline   Reply With Quote
Old 12-01-2016, 11:46   #93
Registered User
 
Exile's Avatar

Join Date: Sep 2010
Location: Land of Disenchantment
Boat: Bristol 47.7
Posts: 2,964
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by Polux View Post
You are correct I expressed myself badly. What I mean is that if I pursued on that course for several more miles a risk of collision would exist and on that situation I would be the stand-on vessel.

I avoid the situation of collision risk before it is even a considered a possibility altering my course, therefore strictly speaking I am not a stand-on vessel since the COLREGS in what regards risk of collision or action to avoid collision are not applicable at that distance.
This seems to contradict what Dockhead just said about well-run commercial ships considering the risk of collision at more like 10nm & making their adjustments accordingly:

In open water, a well-run commercial bridge (not the one discussed in the original post of this thread) has analyzed a crossing, made a decision, and has made a maneuver to create a safe CPA by about 10 miles out.

At 10 miles out, a ship will seem hull down on the horizon, and tiny, from the deck of a sailboat, and most recreational sailors haven't even noticed it yet . . . .
What is more typical is that recreational sailors wake up at 5 or 6 miles out, when the decision point has long passed for the ship.


Obviously the distance involved that triggers the COLREGS "risk of collision" requirements would vary somewhat depending on the type of waters, traffic density, etc., but if the general assumption is as far as 10nm as DH suggests then Polux's described practices -- as well as mine and many other "WAFI's" I'm sure -- is incorrect and potentially dangerous as DH suggests. Very informative, and it sounds like I need to modify my assumptions & reform my SOP's accordingly.

Edit: Just saw that Polux expanded on his post with some good questions about the distances involved. Thanks, Polux.
__________________
Exile is offline   Reply With Quote
Old 12-01-2016, 12:06   #94
Registered User
 
Stu Jackson's Avatar

Join Date: Jan 2011
Location: Cowichan Bay, BC (Maple Bay Marina)
Posts: 6,389
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by Ann T. Cate View Post
.................. I think it was Btrayfors who wrote about turning away from tonnage--on San Francisco Bay, where i learned to sail, we used to call it the Gross Tonnage: they get to be "stand on"--it's gross! Inside the Bay they have constrained ability to maneuver, as well.
So true, Ann. I still sail here, and am constantly amazed at how some skippers of recreational boats have NO situational awareness. None.

The Bay Bridge is a perfect example. The D & E span is a perfect example. It is used by ALL of the ships coming & going into the Oakland Harbor. The wind on the N side is usually there during the summer (sailing) months, but it almost always dies just south of the bridge. This is a NORMAL and daily wind condition at that particular location.

At least once a month (I sail almost weekly) some bozo has his sails up, luffing & flapping and just sitting between D & E, when a ship is approaching. Oftentimes, too often, the five blasts are heard. Bad news. The bozos never bother to look behind them! Maybe they need rear-view mirrors!!!

BTW, the VTS here is superb, CH14, I listen all day to them with scanning on our VHF. A majority of the people I know do NOT KNOW it exists.

The routes for the "traffic" are clearly shown on the charts. While it is busy, it is nowhere near the issues others of you have with the English Channel or SS. The bozos here wouldn't last long there.

My son & I were sailing to Half Moon Bay (18 miles down the coast) last October. As we neared the Golden Gate Bridge, there was an unusual situation: incoming containership, outgoing tug & oil barge and outgoing containership all close together at the bridge (they are usually spaced much further apart). Right in the middle of the span: a sailboat! Air was light, maybe 5 knots, we were motoring with our main up and slowed down to stay east and south of the south tower. That sailboat was passed by all three ships: the inbound one south of him and others to his north, all within five minutes. He hadn't a clue! Clear as a bell day, too. No AIS required, it was a Mark I eyeball day. Holy cow!!! Very scary just watching it all unfold.

Dockhead has written extensively about COLREGS and collision avoidance on this forum, and I recommend that the moderators make a sticky of at least one of his "classics" on the seamanship/boat handling/nav forum section. It should be "required reading" for most skippers.
__________________
Stu Jackson
Catalina 34 #224 (1986) C34IA Secretary
Cowichan Bay, BC, (Maple Bay Marina) SR/FK, M25, Rocna 10 (22#) (NZ model)
Stu Jackson is offline   Reply With Quote
Old 12-01-2016, 13:42   #95
Moderator
 
JPA Cate's Avatar

Join Date: Nov 2011
Location: aboard, cruising in Australia
Boat: Sayer 46' Solent rig sloop
Posts: 10,712
Re: Over-Reliance on AIS -- Collision off Dungeness

Great post, Stu.

You're right, Dockhead writes clearly and understandably about these issues, and such a sticky would be a real service for those folks who are open to it.

FWIW, I've been told the failure to check astern is one of the most common.

Ann

P.S. Jackdale: along portions of the NSW (New South Wales, Australia) coast, the AIS display shows the ships that are drifting (not under command-- two balls in the triangle icon), with their bows pointed into the wind, no trail showing direction.
__________________
Ann, with Jim, aboard US s/v Insatiable II, in Oz, very long term cruisers
JPA Cate is offline   Reply With Quote
Old 12-01-2016, 14:05   #96
Registered User

Join Date: Oct 2015
Location: Germany
Boat: 2ft wide dreaming chair
Posts: 311
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by Ann T. Cate View Post
You're right, Dockhead writes clearly and understandably about these issues, and such a sticky would be a real service for those folks who are open to it.
unfortunately the problem are not the people open to advice as those usualy are out to get some (good advice that is)
__________________
Simonsays is offline   Reply With Quote
Old 12-01-2016, 15:58   #97
Eternal Member
 
monte's Avatar

Cruisers Forum Supporter

Join Date: Jul 2011
Location: Australia
Boat: Lagoon 400
Posts: 3,650
Images: 1
Re: Over-Reliance on AIS -- Collision off Dungeness

We've also come across several ships with heading displays up to 30 degrees from the actual heading. Checking the vector usually clears it up pretty quickly.
__________________
monte is offline   Reply With Quote
Old 13-01-2016, 02:42   #98
Moderator
 
carstenb's Avatar

Cruisers Forum Supporter

Join Date: May 2012
Location: Copenhagen
Boat: Jeanneau Sun Fast 40.3
Posts: 4,942
Images: 1
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by Polux View Post
You are correct I expressed myself badly. What I mean is that if I pursued on that course for several more miles a risk of collision would exist and on that situation I would be the stand-on vessel.

I avoid the situation of collision risk before it is even a considered a possibility altering my course, therefore strictly speaking I am not a stand-on vessel since the COLREGS in what regards risk of collision or action to avoid collision are not applicable at that distance.

Regarding the distance a small sailing boat should be considered a stand on vessel I have some doubts. Sailboats due to the way they sail (with the wind) have many times to alter course due to wind variation or due sailing upwind or downwind.

Don't seem to me logical to me that a small sailingboat stand on distance regarding the risk of collision should be the same regarding a 100 000T bulk carrier and I would like to hear Nigel (and other Merchant ship captains ) about that:

At what distance, regarding a course with a CPA close enough to raise concerns about a possibility of collision, they assume a small sailing boat is the stand on vessel (meaning that they consider the sailboat will not alter their course) and act accordingly altering the ship's course. What is the normal practice?
Nigel and others here are probably better at answering this...

But consider a commercial ship at a speed of 20 knots. From 10nm out - he has a half hour until impact (assuming a collision situation). If he is the give way vessel, spots you and wants a, say 1-2nm clearance to insure he won't run you down, he has to start his maneuvers shortly after spotting you (takes a while to turn a big ship).

So when you spot him - he's probably (assuming a good OOW) already made his course correction or is in the process of doing so. At 5nm out - you spot him and decide "Oh- better get out fo his way" and amke a corrrective maneuver - even though you are the stand on vessel.


You've now screwed up his (correct) maneuver and the game starts. He corrects and then you correct and then you have a crap situation.

In my previous job I spoke with a number of commercial skippers, inncluding ones on high speed catamaran ferries. Their response to me on this question was virtually always - "on open water - we've seen you and we've made maneuvers to avoid you - better just keep going. If you start maneuvering - you'll screw it up"
__________________
I spent most of my money on Booze, Broads and Boats. The rest I wasted - Elmore Leonard
carstenb is offline   Reply With Quote
Old 13-01-2016, 04:08   #99
Registered User

Join Date: Oct 2015
Location: Germany
Boat: 2ft wide dreaming chair
Posts: 311
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by carstenb View Post
In my previous job I spoke with a number of commercial skippers, inncluding ones on high speed catamaran ferries. Their response to me on this question was virtually always - "on open water - we've seen you and we've made maneuvers to avoid you - better just keep going. If you start maneuvering - you'll screw it up"
the best way to distinguish those that have seen you from those who have not is making contact.
if they are not responsive on the radio, seriously start considering options.
if they respond, it already has started to solve the situation.
__________________
Simonsays is offline   Reply With Quote
Old 13-01-2016, 04:45   #100
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 5,765
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by carstenb View Post
Nigel and others here are probably better at answering this...

But consider a commercial ship at a speed of 20 knots. From 10nm out - he has a half hour until impact (assuming a collision situation). If he is the give way vessel, spots you and wants a, say 1-2nm clearance to insure he won't run you down, he has to start his maneuvers shortly after spotting you (takes a while to turn a big ship).

So when you spot him - he's probably (assuming a good OOW) already made his course correction or is in the process of doing so. At 5nm out - you spot him and decide "Oh- better get out fo his way" and amke a corrrective maneuver - even though you are the stand on vessel.


You've now screwed up his (correct) maneuver and the game starts. He corrects and then you correct and then you have a crap situation.

In my previous job I spoke with a number of commercial skippers, inncluding ones on high speed catamaran ferries. Their response to me on this question was virtually always - "on open water - we've seen you and we've made maneuvers to avoid you - better just keep going. If you start maneuvering - you'll screw it up"

I doubt that it is the standard practice, I mean a ship changing course 10nm away from a small sailing vessel (that can or cannot change its course) to avoid a possible collision. Today commercial shipping lowered speeds and most don't go at 20k. Most of the ones that go at that speed and over are fast ferries that are small ships with a big maneuverability.

I would like to hear Nigel opinion about that. Do he change the course of his ship 10NM away from a small sailboat to avoid a possible collision, on the event the sailboat maintains course, being then the sailboat the stand-on vessel?
Polux is offline   Reply With Quote
Old 13-01-2016, 05:55   #101
Long Range Cruiser
 
MarkJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2007
Location: Australian living on "Sea Life" currently in England.
Boat: Beneteau 393 "Sea Life"
Posts: 12,828
Images: 25
Re: Over-Reliance on AIS -- Collision off Dungeness

Ships do change course a long way out if the can. I have seen some make the course change at 10nms, its just a minor change at that range!

The screenshot below is at 2:30 am showing 3 ships diverting around me.

The red ring at the top corners of the shot is 10nms.
So I would think they would have been making their decision well before the changed course. Quite a long way out!

(Also I agree: very very very few shops move at 20 knots. Occasionally a cruise ship will, sometimes a container ship but quite rarely.

__________________
MarkJ is offline   Reply With Quote
Old 13-01-2016, 05:58   #102
Registered User

Join Date: Nov 2007
Location: Probably in an anchorage or a boatyard..
Boat: Ebbtide 33' steel cutter
Posts: 3,540
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by Polux View Post
I doubt that it is the standard practice, I mean a ship changing course 10nm away from a small sailing vessel (that can or cannot change its course) to avoid a possible collision.
Mid atlantic they certainly do, I've watched the doglegs in the ais course to give me more sea room. This on a steel boat with a good radar return. From memory maneuvers were usually complete at about 5Nm, often before you even saw the ship.
__________________
conachair is online now   Reply With Quote
Old 13-01-2016, 08:10   #103
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Cowes (Winter), Baltic (Summer) (the boat!); somewhere in the air (me!)
Boat: Cutter-Rigged Moody 54
Posts: 19,752
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by Polux View Post
I doubt that it is the standard practice, I mean a ship changing course 10nm away from a small sailing vessel (that can or cannot change its course) to avoid a possible collision. Today commercial shipping lowered speeds and most don't go at 20k. Most of the ones that go at that speed and over are fast ferries that are small ships with a big maneuverability.

I would like to hear Nigel opinion about that. Do he change the course of his ship 10NM away from a small sailboat to avoid a possible collision, on the event the sailboat maintains course, being then the sailboat the stand-on vessel?
You doubt, based on guessing. And your collision avoidance technique is based on guessing. But Carsten and others in this thread are not guessing -- they have done the research.

I also did the research. I was like any other WAFI as long as my sailing was limited to U.S. waters, Mediterranean, Caribbean. When I started sailing here -- the busiest waters in the world -- I understood pretty soon that my collision avoidance technique was terrible, and I realized that up to then I had avoided getting run down only because of the skill of the crews of the ships I had encountered.

Concerning that -- most WAFIs remind me of a German teenager I knew when I lived in Germany decades ago. He used to love to get in his car, stand at a side road, getting a running start, and race at full speed across a busy highway. "You see, if I race across fast enough, no one can hit me!" He said, after having done it a few dozen times without an accident.

That's like us -- we've never been run down by a ship; ergo, our collision avoidance technique is effective. Same logical fallacy exactly, and just as dangerous, by the way.


After realizing how little I knew about collision avoidance, I made a big effort to figure it out, including talking to dozens of commercial ship's officers. I even registered in GCaptain and engaged professional mariners on there. I was really surprised by what I found out, and it totally changed my way of looking at collision avoidance.

Don't take our word for it (as if there were any chance of that ); ask around yourself, think about it, work on it. Collision avoidance is a science, which demands a certain amount of learning and work, to achieve even a minimal level of competence. One thing for sure -- if you think you can just look up, recognize a risk of collision, and dart out of the way, as many WAFIs do -- you are definitely doing it wrong.
__________________
"Parce que je suis heureux en mer, et peut-ętre pour sauver mon ame. . . "
Dockhead is offline   Reply With Quote
Old 13-01-2016, 08:23   #104
Registered User
 
Polux's Avatar

Join Date: Nov 2011
Location: Portugal/Med
Boat: Comet 41s
Posts: 5,765
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by MarkJ View Post
Ships do change course a long way out if the can. I have seen some make the course change at 10nms, its just a minor change at that range!

The screenshot below is at 2:30 am showing 3 ships diverting around me.

The red ring at the top corners of the shot is 10nms.
So I would think they would have been making their decision well before the changed course. Quite a long way out!

(Also I agree: very very very few shops move at 20 knots. Occasionally a cruise ship will, sometimes a container ship but quite rarely.

What I see on that picture is that one changed course at 2 or 3nm from your boat, other maybe at 5nm and the third we cannot tell since we cannot see more than 2 or 3 nm of map on the other direction. That is a loong way from 10nm.

Yes I believe it makes all the sense on an Ocean crossing the change of direction to occur sooner. Much less traffic, few changes on the course due to that and a sailboat tacks much less frequently than in coastal sailing.

That is a very nice way to see what really happens out of guessing, being it mine or from Dockhead. Please if somebody can post more maps with situations like that (regarding small sailing boats) we can go out of guessing regarding the average ship changing course 10nm away from a small sailboat. Not saying that it is not possible, just that it don't seem to me the standard practice.

I still would like to hear Nigel opinion about that, I mean regarding changing course at 10nm regarding a sailboat to be standard procedure and what most ships do.
Polux is offline   Reply With Quote
Old 13-01-2016, 09:28   #105
Registered User

Join Date: Jul 2011
Location: Atlantic ICW 29N/81W
Boat: Beneteau Oceanis 36CC, now sold
Posts: 817
Re: Over-Reliance on AIS -- Collision off Dungeness

Quote:
Originally Posted by Dockhead View Post
You doubt, based on guessing. And your collision avoidance technique is based on guessing. But Carsten and others in this thread are not guessing -- they have done the research.

I also did the research. I was like any other WAFI as long as my sailing was limited to U.S. waters, Mediterranean, Caribbean. When I started sailing here -- the busiest waters in the world -- I understood pretty soon that my collision avoidance technique was terrible, and I realized that up to then I had avoided getting run down only because of the skill of the crews of the ships I had encountered.

Concerning that -- most WAFIs remind me of a German teenager I knew when I lived in Germany decades ago. He used to love to get in his car, stand at a side road, getting a running start, and race at full speed across a busy highway. "You see, if I race across fast enough, no one can hit me!" He said, after having done it a few dozen times without an accident.

That's like us -- we've never been run down by a ship; ergo, our collision avoidance technique is effective. Same logical fallacy exactly, and just as dangerous, by the way.


After realizing how little I knew about collision avoidance, I made a big effort to figure it out, including talking to dozens of commercial ship's officers. I even registered in GCaptain and engaged professional mariners on there. I was really surprised by what I found out, and it totally changed my way of looking at collision avoidance.

Don't take our word for it (as if there were any chance of that ); ask around yourself, think about it, work on it. Collision avoidance is a science, which demands a certain amount of learning and work, to achieve even a minimal level of competence. One thing for sure -- if you think you can just look up, recognize a risk of collision, and dart out of the way, as many WAFIs do -- you are definitely doing it wrong.

Very well put DH. Unfortunately a lot of folk think they can act like Florida pedestrians playing chicken whilst crossing busy roads, probably whilst texting on their smartphones. That they get away with it intact has more to do with luck, skill of the commercial vessel OOW, coupled with more open sea areas and less traffic, than it does to their technique.

When we sailed in the congested waters of the English Channel (many, many years, with multiple crossings every year in all weather conditions, day and night there were several occasions when we had satisfactorily resolved our crossing pathway between multiple vessels only to find that a headless chicken WAFI jig by another yacht caused a ship previously clearing us by a large and safe margin to take unexpected avoiding action for the unpredictable WAFI but by so doing getting much closer to us. We observed this both visually and on radar, but back then we had no AIS, in fact AIS did not even exist for most of our time there ( shock horror!) BTW there were plenty of MAFIs as well who treated the lanes as a giant slalom course.

AS you rightly say, collision avoidance is a science and one bound by the COLREGs, which have been agreed internationally without any local nodded through amendments just because it seems like sense to somebody for little boats to alway dodge big boats regardless of the laid down internationally agreed and taught rules.

Predictability is good, unpredictability is bad, very bad, and leads the professional s to treat all recreational vessels as predictably unpredictable.
__________________

__________________
Robin3 is offline   Reply With Quote
Reply

Tags
ais, collision

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Series linking blue reliance water jugs for water tank Ketchgould Plumbing Systems and Fixtures 3 27-02-2013 08:54
Reliance 44 Cutter Ketch Solosailor Monohull Sailboats 58 28-02-2012 18:27
Collision Avoidance in Mexico: AIS or Radar or ? no_bad_days Pacific & South China Sea 27 19-09-2011 16:40
Shelf Reliance Freeze-Dried Foods - Six Months Supply $500 Velocir Provisioning: Food & Drink 4 27-01-2011 07:19
AIS Collision Warning for Own Boat . . . home_maarten OpenCPN 10 28-12-2010 18:29



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 07:46.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.