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seashaw

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Reading about the Wahkuna in YM makes you think and has raised a number points in my mind. If the Wahkuna had AIS could he have called the ship up on the VHF. Although eight hundred quid for a little black box is a lot of money if its stops you being run down it's better than being sat in a liferaft for five hours.
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Mark

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What would he have said ?
"I think you are a bit too close for comf.....aaaaarghhhh.....gurgle gurgle...."

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It used to be said that half the ships going up the channel had a bridge manning of a mate and his Collie, unless the mate needed to visit the heads. Can you train a Collie to answer the vhf, let alone operate the AIS? I know most of them have trouble with rudimentary watchkeeping tasks like making the tea or opening a packet of digestives.

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Surely the point here was that both skippers were aware of each other, but misinterpreted the information in front of them? Having got info, neither ship kept a continuous monitoring of the situation as it developed. Communication with each other would have hardly added anything.

Crossing in fog with ships doing 20+ knots is just asking for trouble. These ships should not be allowed to do this, and should have criminal prosecution if they do.

<hr width=100% size=1>Black Sugar - the sweetest of all
 
> Surely the point here was that both skippers were aware of each other, but
> misinterpreted the information

No it was limitation of the technology, it is complex to use and does not respond quickly enough.

I am sure the experienced yacht skipper would not have ended up with zero boat speed under the bow of the cargo boat given a handheld device displaying accurate collision vectors based on AIS broadcasts.

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I am in the process of fiiting an all singing all dancing radar.I have read the instruction manual and it all seems quite clear how i shall operate it but i guess that at sea in poor vis plenty of motion and clutter on the screen its very different.i guess its rather like looking at an x-ray-you have to look at alot of them and often before you can spot whats going on. we weekend/ summer sailors are at a disadvantage and the more the technology can help us the better.I doubt if classroom courses will show us anything other than how to operate the switches in ideal onditions and practical experience starting in good clear conditions nust be paramount. [raymarine emphasise this in the manual ].I understand that in the quoted article it said that although marpa was available it was not used.

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Why should he call the ship on VHF? The use of VHF for collision aviodence is very bad practice. A little knowledge of the rules and a lot more common sense would have been more help than all the black boxes in the world!

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Why is using the VHF for collision avoidance very bad practice? In the years I was engaged in marine geophysical survey, with an effective length of 2 miles (ship + shallow submerged seismic cable) white flares and VHF were the only means of trying to get shipping to keep clear. Ok, so we went at about the same speed as a yacht but were restricted to gradual turns of 90 degrees and were thus more hampered.

In crowded shipping areas one could usually get a VHF response but not when in open ocean.

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AIS reception integrated with decent chartplotter software would have provided Wahkuna with calculated closest approach distance and time. This would surely at the very least have given the skipper an incentive to monitor his radar target for change of bearing, if not immediately causing him to change course to go astern. An attempt at VHF contact would certainly have been a backup to resolving the situation, given AIS would have provided the ship's name.

It would seem to me that the technology for an AIS receiver is very similar to a dual channel Navtex receiver, apart from the requirement for higher frequency narrow band RF technology, already common in our cheap VHF transcievers. Is it therefore not too much to expect that soon the likes of NASA will be marketing a £200 AIS receiver and be putting the manufactureres of £800 units back in thier holes where they belong? I sincerely hope so as I am sure AIS reception will soon be a must for pleasure boaters in busy shipping areas.

I wonder if commercail shipping might just be a little more cautious when we all have AIS receivers such that they can be identified by all and sundry.

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The fleet instructions for the vessel that hit Wakhuna state that VHF will NOT be used for avoidance of collision. Presumabley because this could add to the confusion.

The point of AIS is not so vessels can be called by name on VHF but that their course and position will be constantly broadcast. A receiver could therefore plot this information on to a chart plotter and extrapolate the course for collision avoidance without the guesswork of inaccurate RADAR

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A skipper who can't take the time to read the (simple) instructions for his own radar is hardly likely to understand or use AIS is he?

<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by rhinorhino on 28/02/2004 15:35 (server time).</FONT></P>
 
If you use AIS data integrated on PC chart plotting software, closest approach distance and time become available, what is there to understand about that?

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