chuzzlewit
Well-Known Member
I have an AIS receiver. I gather that AIS transmitters are available for small leisure boats . Why have I never picked up AIS transmissions from a small boat?
AIS
- Thread starter chuzzlewit
- Start date
WayneS
Well-Known Member
Cos they transmit a different "class" of signal and your receiver may not be able to pick them up.
The latest NASA devices can detect Class A (Normal big ship stuff) and B (The pleasure variety) but I'm not sure about other receivers. Best you check with the manufacturer of your receiver.
BTW, I know that mine is a Class A and B receiver and I have to say that I have never knowingly seen a Class B on my display (Solent Based)
Wayne
The latest NASA devices can detect Class A (Normal big ship stuff) and B (The pleasure variety) but I'm not sure about other receivers. Best you check with the manufacturer of your receiver.
BTW, I know that mine is a Class A and B receiver and I have to say that I have never knowingly seen a Class B on my display (Solent Based)
Wayne
jimi
Well-Known Member
Small craft don't trasmit AIS signals, the AIS receiver is to pick up large craft AIS transmissions so you know where large craft are and what they're doing
davel
Well-Known Member
AIS transmitters are pretty expensive and consume a relatively large amount of electrikery (relative to an AIS receiver). Both these tend to dissuade leisure sailors from fitting them.
rickp
Well-Known Member
Fay's Fantasy at Port Solent never seems to turn their AIS unit off, and it reports itself as a "Pleasure Craft" on ais-live.
There's one boat in Northney which has a Class B transmitter on too - G-Force (a very large princess on the hammerhead), but that one turns it off once berthed.
So there are some around, and thankfully rare - how useful will AIS be when a large proportion of pleasure vessels are transmitting too?
Rick
There's one boat in Northney which has a Class B transmitter on too - G-Force (a very large princess on the hammerhead), but that one turns it off once berthed.
So there are some around, and thankfully rare - how useful will AIS be when a large proportion of pleasure vessels are transmitting too?
Rick
fireball
Well-Known Member
The AIS engines will turn them selves off just for a bit of peace and quiet! /forums/images/graemlins/wink.gif
Channel Ribs
Well-Known Member
They are around 600 to 800 of your earth squids and are rapidly becoming popular with people who do not want RADAR, it gives them a similar piece of mind: they can see the ships and the ships can see them.
Comar Tranceiver
Comar Tranceiver
davel
Well-Known Member
Yep, like I said - pretty expensive !
/forums/images/graemlins/smile.gif
/forums/images/graemlins/smile.gif
Richard10002
Well-Known Member
[ QUOTE ]
So there are some around, and thankfully rare - how useful will AIS be when a large proportion of pleasure vessels are transmitting too?
[/ QUOTE ]
All of these vessels "transmit" when you have your radar on, so not sure what the difference is.
(I know they dont transmit, they reflect, but same number of dots on the screen).
So there are some around, and thankfully rare - how useful will AIS be when a large proportion of pleasure vessels are transmitting too?
[/ QUOTE ]
All of these vessels "transmit" when you have your radar on, so not sure what the difference is.
(I know they dont transmit, they reflect, but same number of dots on the screen).
Richard10002
Well-Known Member
[ QUOTE ]
Yep, like I said - pretty expensive !
/forums/images/graemlins/smile.gif
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Given that they would tell big ships that you are there, (Ouzo/PoB???), aswell as providing lots of useful info, it doesnt seem a high price to pay.
Particularly when these See-Me things seem to be around £400 and, IIRC, they only get seen on one of the radar bands.
AIS transmitting would seem to resolve many of the issues relating to being seen by big ships and, presumably, the big ship system would have a record of having seen you, so no excuse for OOWs.
Yep, like I said - pretty expensive !
/forums/images/graemlins/smile.gif
[/ QUOTE ]
Given that they would tell big ships that you are there, (Ouzo/PoB???), aswell as providing lots of useful info, it doesnt seem a high price to pay.
Particularly when these See-Me things seem to be around £400 and, IIRC, they only get seen on one of the radar bands.
AIS transmitting would seem to resolve many of the issues relating to being seen by big ships and, presumably, the big ship system would have a record of having seen you, so no excuse for OOWs.
rickp
Well-Known Member
My chart plotter isn't trying to do CPA calculations on each radar dot though (and even MARPA has a limit of 10 I believe), where as it is (currently) doing that for all AIS targets within a 5nm range. Its okay with 15 targets. I'm trying to imagine it coping with the Solent on a weekend though...
Rick
Rick
Richard10002
Well-Known Member
[ QUOTE ]
They are around 600 to 800 of your earth squids
Comar Tranceiver
[/ QUOTE ]
£525 including free shipping - getting close to being a no brainer??
any drawbacks with this one?
They are around 600 to 800 of your earth squids
Comar Tranceiver
[/ QUOTE ]
£525 including free shipping - getting close to being a no brainer??
any drawbacks with this one?
FinesseChris
Well-Known Member
Comar:
Useful features:
"Transmit Off facility to conserve power or for covert use"
Covert use? What can they be thinking of? Like that chap who hit the Portsmouth barrier with his girlfriend on board?
C
Useful features:
"Transmit Off facility to conserve power or for covert use"
Covert use? What can they be thinking of? Like that chap who hit the Portsmouth barrier with his girlfriend on board?
C
Amphitrite
Well-Known Member
Power comsumption of a Class B is around 6 W, and transmitting can be switched off if power really should be an issue... Installation is pretty straight-forward, they include a GPS which could serve as a backup and costs are from 515,- GBP
RestlessL
Well-Known Member
So, if I only have £600 left in the refit pot this winter, do I spend it on a Sea Me, or a Comar AIS tranceiver ?
The Sea Me will enhance visibility, but only to X-band radar, so not sure if it will help mid-channel (I already have a Firdell Blipper)
The Comar will show my position to any ship keeping a watch on AIS - but how many of them do (POB didn't).
John
The Sea Me will enhance visibility, but only to X-band radar, so not sure if it will help mid-channel (I already have a Firdell Blipper)
The Comar will show my position to any ship keeping a watch on AIS - but how many of them do (POB didn't).
John
fireball
Well-Known Member
How many commercial vessels actually use AIS as a collision avoidance tool - do they overlay it on charts? do they have it on radar like displays?
Certainly neither on the bridges that I've visited ... they still use Radar as a primary tool ... next to Mk1 Eyeballs.
Certainly neither on the bridges that I've visited ... they still use Radar as a primary tool ... next to Mk1 Eyeballs.
Oldhand
Well-Known Member
If you were in Lymington you would pick up Class B transmissions from pleasure vessels almost continuously, there's one motor yacht that seems to leave their AIS on continuously even when docked.