AIS as Radar substitute??

[roger]

I recently went to a talk given buy a guy from National Coastwatch (the fellows who actually look out to sea). He mentioned that they had AIS and radar at some sites. I saked him for his estimate of the percentage of shipping that should have AIS that were using it. His estimate was "around 60%".
Many ship operators dont have it on. They might be doing something illegal; there could be commercial considerations ( getting a berth quickly at the next port etc.) or they miight just not like regulation. Apparently many vessels replace ships nmes etc. with obscenities.
He also said that the authorities were going to tighten the enforcement of regulations.
My immediate reaction was that AIS was little use as a warning system in poor visibility as a radar substitute.
This is the first time I've managed to get anything like an official view about AIS.
Have you had any relevant experiences?

 

[tangomoon]

Look it up but I believe AIS will not show anything below 300 tons.

 

[fluffc]

AIS was never intended as a substitute for Radar, but merely to compliment it.

 

[BlueSkyNick]

[ QUOTE ]
AIS was never intended as a substitute for Radar, but merely to compliment it.

[/ QUOTE ] Fully agree, and the fact that only 60% of intended vessels are transmitting AIS properly reinforces the point that it is no substitute for radar at all.

 

[BrendanS]

any leisure vessel can fit class B AIS if they want.

 

[doug748]

There is a serving merchant navy officer who reported on these matters a while ago. He said he had seen some ships that were not complying, certainly not 40%.
Perhaps the coastguard's 40% figure included those ship that are not required to show themselves, warships, those under 300 tons etc.

 

[Woodentop]

[ QUOTE ]
Perhaps the coastguard's 40% figure included those ship that are not required to show themselves, warships, those under 300 tons etc.

[/ QUOTE ]

Don not confuse HM Coastguard with the National Coastwatch Institute.

 

[graham]

National Coast Watch is a voluntary organisation that man some of the disused coast guard look out stations .

In my experience using AIS on a daily basis the occasional ship will be not complying but well over 90% do.probably because non complying would be noted by any VTS areas they pass through. Wether a significant number of ships shut them down when well out at sea I dont know .

This still doesnt alter the fact that theres an awful lot of small ships ,fishing vessels pleasure craft etc which dont require AIS due to their size but could quite easilly sink you in a collision .