Peppermint
Well-Known Member
Re: I\'m curious....
Would you have made these passages in poor viz without your AIS?
Would you have made these passages in poor viz without your AIS?
AIS 'Radar' - Does it do it for you?
- Thread starter Robin
- Start date
fireball
Well-Known Member
Re: If...
[ QUOTE ]
If radar systems only showed the vessels which wanted to be shown, I wonder how many of us would bother buying radar?
[/ QUOTE ]
I wouldn't pay >£1k for a Radar unit if I couldn't be 95% certain that it was giving me the whole picture.
However, I think that £150 for an AIS engine or £250 to include the display, for a system that gives you a lot of the shipping ADDING to your normal lookout is a reasonable expenditure as long as the operators realise its limitations. Please note that in both my posts so far I have NOT referred to the AIS unit as a RADAR .... which I still believe is a misleading title.
One example where I could've used AIS happily ... sailing back from Poole a few weeks ago, into the Solent via the Needles, we came across a coaster comming in the same way, had we not seen it (it came from our back quarter) we would've met at the entrance of the channel at the same time (its always the same, no matter how fast or slow you sail). Obviously we saw it in plenty of time and put in an extra tack to let it go through first (I'm polite you see!). Had I had AIS onboard though, we could probably have picked up its course earlier on and slowed our passage suitably so we wouldn't have met to start with. It certainly wasn't a situation where you'd have RADAR on for anything other than training, but the low wattage of an AIS unit means that it would be on all the time.
[ QUOTE ]
If radar systems only showed the vessels which wanted to be shown, I wonder how many of us would bother buying radar?
[/ QUOTE ]
I wouldn't pay >£1k for a Radar unit if I couldn't be 95% certain that it was giving me the whole picture.
However, I think that £150 for an AIS engine or £250 to include the display, for a system that gives you a lot of the shipping ADDING to your normal lookout is a reasonable expenditure as long as the operators realise its limitations. Please note that in both my posts so far I have NOT referred to the AIS unit as a RADAR .... which I still believe is a misleading title.
One example where I could've used AIS happily ... sailing back from Poole a few weeks ago, into the Solent via the Needles, we came across a coaster comming in the same way, had we not seen it (it came from our back quarter) we would've met at the entrance of the channel at the same time (its always the same, no matter how fast or slow you sail). Obviously we saw it in plenty of time and put in an extra tack to let it go through first (I'm polite you see!). Had I had AIS onboard though, we could probably have picked up its course earlier on and slowed our passage suitably so we wouldn't have met to start with. It certainly wasn't a situation where you'd have RADAR on for anything other than training, but the low wattage of an AIS unit means that it would be on all the time.
Robin
Well-Known Member
Re: AIS \'Radar\' - Does it do it for you?
Chris
Yes I wouldn't contemplate one without having radar first. You and Parahandy have the PC/laptop engine version which I guess will also be much clearer and perhaps even tweakable to display in heading up form?
The tiny NASA screen and North Up only option is the downside to the low power consumption of the NASA set as compared to a PC/laptop version. We carry a laptop on board for longer passages/holidays but rarely on a local weekend. However my laptop is a work tool too (& paid for by me...) so is packed away carefully in it's case in the dry when we are underway, it comes out for passage planning mostly but we also have weatherfax and RTTY as well as the planning and tidal software. My Sony laptop is somewhat power hungry too and runs via an inverter, taking about the same amps all up as the radar!
Robin
Chris
Yes I wouldn't contemplate one without having radar first. You and Parahandy have the PC/laptop engine version which I guess will also be much clearer and perhaps even tweakable to display in heading up form?
The tiny NASA screen and North Up only option is the downside to the low power consumption of the NASA set as compared to a PC/laptop version. We carry a laptop on board for longer passages/holidays but rarely on a local weekend. However my laptop is a work tool too (& paid for by me...) so is packed away carefully in it's case in the dry when we are underway, it comes out for passage planning mostly but we also have weatherfax and RTTY as well as the planning and tidal software. My Sony laptop is somewhat power hungry too and runs via an inverter, taking about the same amps all up as the radar!
Robin
Robin
Well-Known Member
Re: AIS \'Radar\' - Does it do it for you?
[ QUOTE ]
Since then we've crossed back from the Channel Islands in poor vis (about a mile or less). The AIS Radar gave us the warning that we needed. But this was in or close to an area covered by VTS, and we reckoned that there would have been warnings if a big fast ship had been transitting the area without its AIS operating
[/ QUOTE ]
I'm afraid that is not what happens! Joburg Traffic Control is the one which covers Casquets TSS and I have never heard then put out such a warning. I have however heard them many times this year calling vessels on Ch16 as 'ship in position...etc' just as they used to pre-AIS (but in much lesser numbers) which implies they still have vessels on their radar not displaying a corresponding AIS identity tag.
Also in similar poor visibility we recently came across a tug with a huge barge full of boulders headed west some 11mls south of the Needles as we were northbound home to Poole. We didn't recognise the tug & tow as such until about half a mile away, not a problem in fact but it could have been if the vis was a bit worse. I called Solent CG and asked if they were aware as we had heard no Securite calls from the tug nor anything from Solent who had just put out a 'Maritime Safety Broadcast'. The MSB from solent merely repeated a then 12 hour old Inshore Forecast (incorrect anyway as for one thing it said visibility 'good' and we had about 1ml and the wind strength/direction was also wrong), Solent told me they had no knowledge of the tug/tow, so presumably there was no AIS tag on that one either!
Faith is a wonderful thing!
Robin
[ QUOTE ]
Since then we've crossed back from the Channel Islands in poor vis (about a mile or less). The AIS Radar gave us the warning that we needed. But this was in or close to an area covered by VTS, and we reckoned that there would have been warnings if a big fast ship had been transitting the area without its AIS operating
[/ QUOTE ]
I'm afraid that is not what happens! Joburg Traffic Control is the one which covers Casquets TSS and I have never heard then put out such a warning. I have however heard them many times this year calling vessels on Ch16 as 'ship in position...etc' just as they used to pre-AIS (but in much lesser numbers) which implies they still have vessels on their radar not displaying a corresponding AIS identity tag.
Also in similar poor visibility we recently came across a tug with a huge barge full of boulders headed west some 11mls south of the Needles as we were northbound home to Poole. We didn't recognise the tug & tow as such until about half a mile away, not a problem in fact but it could have been if the vis was a bit worse. I called Solent CG and asked if they were aware as we had heard no Securite calls from the tug nor anything from Solent who had just put out a 'Maritime Safety Broadcast'. The MSB from solent merely repeated a then 12 hour old Inshore Forecast (incorrect anyway as for one thing it said visibility 'good' and we had about 1ml and the wind strength/direction was also wrong), Solent told me they had no knowledge of the tug/tow, so presumably there was no AIS tag on that one either!
Faith is a wonderful thing!
Robin
graham
Well-Known Member
Re: AIS \'Radar\' - Does it do it for you?
Speaking as someone who uses AIS on a daily basis in my work IMHO An AIS monitor is a very usefull addition to the information available to you in poor vis.
BUT it isnt a radar and the information on it can be innacurate or incomplete on occasions..
Speaking as someone who uses AIS on a daily basis in my work IMHO An AIS monitor is a very usefull addition to the information available to you in poor vis.
BUT it isnt a radar and the information on it can be innacurate or incomplete on occasions..
ParaHandy
Well-Known Member
Re: AIS \'Radar\' - Does it do it for you?
Running shipplotter on the laptop gives both map and "radar" display and the latter can be course or north up. SeaClear does not provide this facility.
Power consumption became quite important for unforeseen reasons. Windows XP won't come out of hibernation with a serial USB connected which means the power saving settings require it to be on permanently. (Microsoft know about it and are supposedly about to fix it) However, setting screen to minimum and avoiding any of the more fancy stuff the software will do, keeps the disc useage down. Not a huge problem as when you're running AIS you'd want it on permanently anyway. It's also powered from a DC to DC supply rather than an inverter and that must help.
Running shipplotter on the laptop gives both map and "radar" display and the latter can be course or north up. SeaClear does not provide this facility.
Power consumption became quite important for unforeseen reasons. Windows XP won't come out of hibernation with a serial USB connected which means the power saving settings require it to be on permanently. (Microsoft know about it and are supposedly about to fix it) However, setting screen to minimum and avoiding any of the more fancy stuff the software will do, keeps the disc useage down. Not a huge problem as when you're running AIS you'd want it on permanently anyway. It's also powered from a DC to DC supply rather than an inverter and that must help.
Robin
Well-Known Member
Re: AIS \'Radar\' - Does it do it for you?
I take it that you are running chartplotting on the laptop too, whereas we have dedicated plotters consuming 0.5A only. Also in our case I would have to buy yet another GPS to feed the laptop as well as the AIS engine although at least we already have the spare VHF aerial mounted. However the course-up ability would be a big plus over the NASA display, even without the big screen laptop view. Another irritation I would find is all the extra cabling required to connect GPS to Laptop, AIS to laptop, VHF aerial to laptop, as well power cable to laptop!
Presumably the course-up is from GPS COG rather than heading-up as displayed on the radar?
Robin
I take it that you are running chartplotting on the laptop too, whereas we have dedicated plotters consuming 0.5A only. Also in our case I would have to buy yet another GPS to feed the laptop as well as the AIS engine although at least we already have the spare VHF aerial mounted. However the course-up ability would be a big plus over the NASA display, even without the big screen laptop view. Another irritation I would find is all the extra cabling required to connect GPS to Laptop, AIS to laptop, VHF aerial to laptop, as well power cable to laptop!
Presumably the course-up is from GPS COG rather than heading-up as displayed on the radar?
Robin
ParaHandy
Well-Known Member
Re: AIS \'Radar\' - Does it do it for you?
by definition, AIS is ground based. but you can set either heading or COG but not sure what good it will do you ...
by definition, AIS is ground based. but you can set either heading or COG but not sure what good it will do you ...
ChrisE
Well-Known Member
Re: AIS \'Radar\' - Does it do it for you?
Are you sure that you will need another GPS? We have a splitter that feeds the chartplotter and the AIS engine and the output from that feeds the PC chartplotter, if you see what I mean.
Are you sure that you will need another GPS? We have a splitter that feeds the chartplotter and the AIS engine and the output from that feeds the PC chartplotter, if you see what I mean.
Robin
Well-Known Member
Re: AIS \'Radar\' - Does it do it for you?
Only from the point of view of making a direct visual comparison between radar screen echoes and AIS screen tags, ie radar sees echo 30 degs off port bow, which one is this on the AIS display. This needs a bit of concentration (therefore possibility of errors) if the radar looks straight ahead whilst the AIS displays in North-Up or even Course-Up in a cross tide. If it can display in head-up format it would need a compass input as well, so need to be linked to the main NMEA/Seatalk Bus rather than to say a USB plug in GPS sensor.
Only from the point of view of making a direct visual comparison between radar screen echoes and AIS screen tags, ie radar sees echo 30 degs off port bow, which one is this on the AIS display. This needs a bit of concentration (therefore possibility of errors) if the radar looks straight ahead whilst the AIS displays in North-Up or even Course-Up in a cross tide. If it can display in head-up format it would need a compass input as well, so need to be linked to the main NMEA/Seatalk Bus rather than to say a USB plug in GPS sensor.
tome
Well-Known Member
Re: AIS \'Radar\' - Does it do it for you?
If you have GPS linked to Seatalk, you will get both compass and gps nmea on a single connection via a seatalk bridge.
If you have GPS linked to Seatalk, you will get both compass and gps nmea on a single connection via a seatalk bridge.
Robin
Well-Known Member
Re: AIS \'Radar\' - Does it do it for you?
[ QUOTE ]
If you have GPS linked to Seatalk, you will get both compass and gps nmea on a single connection via a seatalk bridge.
[/ QUOTE ]
We have just that, but how to get it into the laptop is another question! For the time being anyway I prefer to save the amps and keep the laptop dry and safe.
I'm a bit wary these days of getting NMEA bits talking to each other, I still don't have our NASA DSC set running from our Navman plotter/GPS. I spoke with Navman again at SIB last week and they suggest I try a 1K resistor across the NMEA leads on the NASA to stabilise the voltage, otherwise I may sell the NASA set and buy a Navman one. It is another reason I'm not rushing to buy a NASA AIS 'Radar', it could end up with no positional data just like their VHF!
Robin
[ QUOTE ]
If you have GPS linked to Seatalk, you will get both compass and gps nmea on a single connection via a seatalk bridge.
[/ QUOTE ]
We have just that, but how to get it into the laptop is another question! For the time being anyway I prefer to save the amps and keep the laptop dry and safe.
I'm a bit wary these days of getting NMEA bits talking to each other, I still don't have our NASA DSC set running from our Navman plotter/GPS. I spoke with Navman again at SIB last week and they suggest I try a 1K resistor across the NMEA leads on the NASA to stabilise the voltage, otherwise I may sell the NASA set and buy a Navman one. It is another reason I'm not rushing to buy a NASA AIS 'Radar', it could end up with no positional data just like their VHF!
Robin