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Old 11-01-2016, 07:58   #61
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Re: Over-Reliance on AIS -- Collision off Dungeness

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Don't need to swim the Singapore straits... just walk on the polution!
Bit like this dude I photographed in the middle of the four lane TSS… he he
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Old 11-01-2016, 08:01   #62
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Re: Over-Reliance on AIS -- Collision off Dungeness

Speaking of AIS... doesn't it make sense for the aids to navigation to show on AIS? I believe virtual AIS can be broadcast. Is this a common practice? If not why not?
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Old 11-01-2016, 09:02   #63
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Re: Over-Reliance on AIS -- Collision off Dungeness

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I don't really want to make this a COLREGS thread, but Polux, this is very bad anticollision practice. I cannot fail to speak up.

Don't change course AT ALL when you are the stand-on vessel, until you've given the other vessel a chance to maneuver. You are obligated to hold course and speed exactly so that he gets his chance to take the active role in the crossing. The whole science of collision avoidance doesn't work if you just jink around willy-nilly as you please, in a crossing with another vessel.

Once you do start maneuvering yourself (either before "risk of collision" exists, so probably at least 10 miles out) OR after you are permitted to start maneuvering as provided in the rules, THEN do not EVER make a "small change of course", but a dramatic one which will not be mistaken by the other vessel. This is specifically mentioned in the COLREGS, and is a serious and important point.

"Small changes of course" during a crossing with another vessel are very dangerous and are specifically prohibited by the COLREGS, because they can mess up the calculated CPA without, however, being noticeable to the other vessel. Especially bad is small, repeated changes of course (or speed) carried out by a skipper just eyeballing it, rather than plotting and working up a proper CPA. Lots of collisions happen because of this.
That makes not any sense saying that. I change always my course when there is a possibility of a close encounter and close for me regarding a big ship is at least 1 nm. I change the course very early and always to pass on the stern of the big ship and I alter it many miles away from that possible encounter, much sooner the big ship would be making any course alteration to avoid me.

I fail to understand how this is not common sense good seamanship practice and a very bad anti collision practice.
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Old 11-01-2016, 09:13   #64
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Re: Over-Reliance on AIS -- Collision off Dungeness

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Driving the wrong way up a TSS in the middle of the night between tankers like that fishing boat in the image is a bit beyond my pay grade though....
yeah - that was what Dockhead and I ended up doing during our run up the channel in a storm. Simply couldn't cross at right angles like we were supposed - force 8/9 and 6 meter waves - we would have broached.

Coast guard gave us permission - still pretty cool. Like I said earlier - Just peachy! Can't wait to do it again! (yeah right - not in a million years)
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Old 11-01-2016, 09:18   #65
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Re: Over-Reliance on AIS -- Collision off Dungeness

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yeah - that was what Dockhead and I ended up doing during our run up the channel in a storm. Simply couldn't cross at right angles like we were supposed - force 8/9 and 6 meter waves - we would have broached.

Coast guard gave us permission - still pretty cool. Like I said earlier - Just peachy! Can't wait to do it again! (yeah right - not in a million years)
give me a call if you need crew for stuff like that.
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Old 11-01-2016, 09:21   #66
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Re: Over-Reliance on AIS -- Collision off Dungeness

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yeah - that was what Dockhead and I ended up doing during our run up the channel in a storm. Simply couldn't cross at right angles like we were supposed - force 8/9 and 6 meter waves - we would have broached.

Coast guard gave us permission - still pretty cool. Like I said earlier - Just peachy! Can't wait to do it again! (yeah right - not in a million years)
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Old 11-01-2016, 09:29   #67
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pirate Re: Over-Reliance on AIS -- Collision off Dungeness

Polux.. if you have a good reflector and they are vigilant they'll spot you while they are still hull down on the horizon and your still trying to decide what that little grey smudge is.. also.. any course change the navigator recommends will be 5degrees max that far off.. to small by far to be noticed by you..
Personally crossing TSZ's I stand on till the ship is 3 miles away then line it up with a stanchion or something.. if its holding steady by 1nm I'll switch to a course 180 to his then gradually go back on course as he closes and I pass his stern.. the Poole-Cherbourg run was an often made trip back in the 70's, 80's and early 90's when booze n baccy was 1/3rd the price of the UK..
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Old 11-01-2016, 09:53   #68
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Re: Over-Reliance on AIS -- Collision off Dungeness

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Polux.. if you have a good reflector and they are vigilant they'll spot you while they are still hull down on the horizon and your still trying to decide what that little grey smudge is.. also.. any course change the navigator recommends will be 5degrees max that far off.. to small by far to be noticed by you..
Personally crossing TSZ's I stand on till the ship is 3 miles away then line it up with a stanchion or something.. if its holding steady by 1nm I'll switch to a course 180 to his then gradually go back on course as he closes and I pass his stern.. the Poole-Cherbourg run was an often made trip back in the 70's, 80's and early 90's when booze n baccy was 1/3rd the price of the UK..

You need to get out in more modern boats. On the open ocean with AIS, I see ships before they see me because my transmit power is lower. Even if I am the stand on vessel, I make my turn to avoid them before they know I am there. When I pop up on their AIS display, there is a CPA of 2 miles and everyone is happy.

A ship's 5 degree turn easily shows up on the AIS when they are 15-20 miles away. Not so from a small boat because the idiots who make Class B transponders insist on using unfiltered COG data.
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Old 11-01-2016, 09:55   #69
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Re: Over-Reliance on AIS -- Collision off Dungeness

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...
A ship's 5 degree turn easily shows up on the AIS when they are 15-20 miles away. Not so from a small boat because the idiots who make Class B transponders insist on using unfiltered COG data.
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Old 11-01-2016, 10:01   #70
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Re: Over-Reliance on AIS -- Collision off Dungeness

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Polux.. if you have a good reflector and they are vigilant they'll spot you while they are still hull down on the horizon and your still trying to decide what that little grey smudge is.. also.. any course change the navigator recommends will be 5degrees max that far off.. to small by far to be noticed by you....
At night I use always radar and I know how weak a sailboat signal can be specially if there are big waves.

And regarding being visible on the radar it is needed that someone is looking at it or that the alarm is on. I don't like to take chances with that and if I consider that a situation can be potentially dangerous I always make sure that I am being seen. Then I trust that each of us will take the right measures to avoid a collision.
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Old 11-01-2016, 10:19   #71
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Re: Over-Reliance on AIS -- Collision off Dungeness

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You need to get out in more modern boats. On the open ocean with AIS, I see ships before they see me because my transmit power is lower. Even if I am the stand on vessel, I make my turn to avoid them before they know I am there. When I pop up on their AIS display, there is a CPA of 2 miles and everyone is happy.
...
You can also do that using radar or your eyes. That was what I was talking about regarding changing course to avoid any situation with a close CPA with a ship. If the CPA is not a close one (I mean several miles away) than there is not any risk of collision, colregs will not apply and there will not be a stand on vessel.
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Old 11-01-2016, 10:36   #72
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Re: Over-Reliance on AIS -- Collision off Dungeness

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Speaking of AIS... doesn't it make sense for the aids to navigation to show on AIS? I believe virtual AIS can be broadcast. Is this a common practice? If not why not?
It is common practice.
Ships Map - Vessel Tracking & AIS Positions Map | AIS Marine Traffic
On the left click on the funnel icon to filter, you can turn everything off apart from navigation aids.

Lots of them.
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Old 11-01-2016, 10:38   #73
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pirate Re: Over-Reliance on AIS -- Collision off Dungeness

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At night I use always radar and I know how weak a sailboat signal can be specially if there are big waves.

And regarding being visible on the radar it is needed that someone is looking at it or that the alarm is on. I don't like to take chances with that and if I consider that a situation can be potentially dangerous I always make sure that I am being seen. Then I trust that each of us will take the right measures to avoid a collision.
I know I'll get a beating for this but..
Sorry guys.. been using Mk1 eyeball to long to give it up now.. at least while its still working well.
Deliveries.. matters not if the gears on board or not.. it will not get used.. same goes for bludi watermakers...
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Old 11-01-2016, 10:51   #74
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Re: Over-Reliance on AIS -- Collision off Dungeness

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It is common practice.
Ships Map - Vessel Tracking & AIS Positions Map | AIS Marine Traffic
On the left click on the funnel icon to filter, you can turn everything off apart from navigation aids.

Lots of them.

Didn't work for me in LIS... I see no aids to navigation...
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Old 11-01-2016, 11:07   #75
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Re: Over-Reliance on AIS -- Collision off Dungeness

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That makes not any sense saying that. I change always my course when there is a possibility of a close encounter and close for me regarding a big ship is at least 1 nm. I change the course very early and always to pass on the stern of the big ship and I alter it many miles away from that possible encounter, much sooner the big ship would be making any course alteration to avoid me.

I fail to understand how this is not common sense good seamanship practice and a very bad anti collision practice.
It is very bad, very dangerous practice specifically forbidden by the COLREGS, to do as you suggest, unless it's done (a) prior to "risk of collision arising", as defined in the Rules; and (b) done with a large, not small change of course and/or speed which will be evident to the other bridge. You should study collision avoidance some. Both the rules, and practical techniques.

"Prior to risk of collision arising" will be earlier than most recreational sailors can even detect a potential collision, so this condition is hard to fulfill. It will be no less than about 10 miles out, which is the usual decision point for well-run commercial ships in open water. If you do your small change of course at, say 6 miles out, and you were the stand-on vessel, what you most likely don't understand is that the ship has already changed course for a safe pass. Your small alteration of course has a 50% chance of screwing up his solution, and since the course change was small, there is significant risk that he will fail to notice it, at least for some time, and this creates a really serious risk of collision, which is why the Rules are written the way they are.

If you are not using AIS, then it takes serious work to determine a risk of collision from 10 miles out. It's pretty much impossible to do it with a HBC from this distance, but can be done with good compass binoculars, or with radar.

If you are not able to determine risk of collision from this distance, then you must not do any course alterations during the "stand on" phase of the crossing. You are obligated to give the ship the chance to resolve the situation -- and he can't do it if you are jigging around changing course or speed. It is your obligation to hold course and speed for a certain amount of time to allow for this.

At a certain point, if you reasonably believe that he has not taken adequate measures, you get the right to maneuver yourself. Note that you CANNOT determine whether he has taken adequate measure with your bare eyes. You have to use AIS, radar with a decent plot, or very good technique with a HBC. What looks like a collision course with your bare eyes might well be a safe CPA, and you will screw up his maneuver.

If you do determine this, then your manuever MUST be a large, obvious one.
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