D
Deleted member 478
Guest
Are they worth it?
LadyInBed
Well-Known Member
If you truck across the shipping lanes a lot, then yes.
AlistairC
Well-Known Member
I think AIS is worth it, especially if you have software which tells you whether that ferry that looks like its coming straight for you is going to go behind or in front. You can get going for <£200 if you already have a chart plotter
Marpa is quite expensive, and any ships that you wouldnt be able to avoid should a close quarters situation develop should have AIS.
Marpa is quite expensive, and any ships that you wouldnt be able to avoid should a close quarters situation develop should have AIS.
D
Deleted member 478
Guest
Thanks. Any recommendations for an AIS system? I think all new radars come with MARPA as standard and so I will have it anyway.
FWIW, I have ordered the Raymarine radar and E80 plotter thingie.
FWIW, I have ordered the Raymarine radar and E80 plotter thingie.
tome
Well-Known Member
Re: AIS & MARPA
Good choice. Avoid the cheap NASA AIS with the E80 and buy a Raymarine AIS250 instead, even though it'll cost more
You'll also need a fast heading sensor if you want serious MARPA
Good choice. Avoid the cheap NASA AIS with the E80 and buy a Raymarine AIS250 instead, even though it'll cost more
You'll also need a fast heading sensor if you want serious MARPA
D
Deleted member 478
Guest
Re: AIS & MARPA
Ouch! The Raymarine AIS250 requires a large pile of folding stuff.
Ouch! The Raymarine AIS250 requires a large pile of folding stuff.
AlistairC
Well-Known Member
Re: AIS & MARPA
My NASA AIS works like a dream. I have it fed from the masthead aerial.
My NASA AIS works like a dream. I have it fed from the masthead aerial.
tome
Well-Known Member
Re: AIS &amp; MARPA
I'm using the NASA unit with the E80 and it drops out regularly (just when you need it). The output drive level of the NASA AIS doesn't meet NMEA specs so it's fine with a PC but not much use elsewhere
I'm using the NASA unit with the E80 and it drops out regularly (just when you need it). The output drive level of the NASA AIS doesn't meet NMEA specs so it's fine with a PC but not much use elsewhere
AlistairC
Well-Known Member
Re: AIS &amp; MARPA
Aah I am using it on a PC. I'm guessing the output is probably TIA/EIA232 rather than 422 signal levels. However the NMEA standard recommends 422, it does not require it. Raymarine stuff is great though.
Aah I am using it on a PC. I'm guessing the output is probably TIA/EIA232 rather than 422 signal levels. However the NMEA standard recommends 422, it does not require it. Raymarine stuff is great though.
jamesjermain
Well-Known Member
Not quite all Radar are MARPA capable and those that are should be equipped with a gyro compass before they can give accurate CPA information.
Having used MARPA on several occasions I think it is absolutely fabulous but I accept that it is expensive and not affordable by all (myself included). AIS is also great but flawed. There are too many vessels out there who don't, or won't turn it on or don't or won't have it fitted. Some of these are the most difficult to avoid - fishing boats, high speed motor boats, grey-funnel cruisers etc. also in some crowded waters the screen is so full of information I fear things might get missed.
Having said that, for the price, NASAs AIS radar is hard to ignore.
Having used MARPA on several occasions I think it is absolutely fabulous but I accept that it is expensive and not affordable by all (myself included). AIS is also great but flawed. There are too many vessels out there who don't, or won't turn it on or don't or won't have it fitted. Some of these are the most difficult to avoid - fishing boats, high speed motor boats, grey-funnel cruisers etc. also in some crowded waters the screen is so full of information I fear things might get missed.
Having said that, for the price, NASAs AIS radar is hard to ignore.
tome
Well-Known Member
Re: AIS &amp;amp; MARPA
The NASA site claims it's RS232, but then it also claims that the output is NMEA 2000 which it isn't. I'll check next time I'm down but I suspect that the output is 3.3V TTL which doesn't even meet RS232. Fine with a PC which is very tolerant of levels and baud rates
The NMEA 0183 standard (which I have in front of me) states that a talker "shall meet, at a minimum, the requirements of EIA-422-A" so def not a recommendation
The NASA site claims it's RS232, but then it also claims that the output is NMEA 2000 which it isn't. I'll check next time I'm down but I suspect that the output is 3.3V TTL which doesn't even meet RS232. Fine with a PC which is very tolerant of levels and baud rates
The NMEA 0183 standard (which I have in front of me) states that a talker "shall meet, at a minimum, the requirements of EIA-422-A" so def not a recommendation
iangrant
Well-Known Member
Re: AIS &amp;amp; MARPA
Tome - you sound very knowlegeable about all this rs232 and 422 and levels is this another skill that goes along with the sewing.
There are lots of experts on this forum and i wonder who to believe with all this complicated talk, is the NASA no good, can i not use it as radar, it says it is, can i link it to my compass to get a heading?
Tome - you sound very knowlegeable about all this rs232 and 422 and levels is this another skill that goes along with the sewing.
There are lots of experts on this forum and i wonder who to believe with all this complicated talk, is the NASA no good, can i not use it as radar, it says it is, can i link it to my compass to get a heading?
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Re: AIS & MARPA
Can the output from the Raymarine AIS250 be output to a screen other than a Raymarine plotter? I've got the RL series radar and chartplotter which doesn't have AIS integration - so I need a cheapish screen that it can interface with. Any ideas?
Can the output from the Raymarine AIS250 be output to a screen other than a Raymarine plotter? I've got the RL series radar and chartplotter which doesn't have AIS integration - so I need a cheapish screen that it can interface with. Any ideas?
tome
Well-Known Member
Re: AIS &amp;amp;amp; MARPA
Well, one thing leads onto another, innit?
Well, one thing leads onto another, innit?
tome
Well-Known Member
Re: AIS &amp; MARPA
Not as far as I know, it requires AIS support and a fast (38,400 baud) serial port. I believe it's only the C and E series which provide AIS support
Not as far as I know, it requires AIS support and a fast (38,400 baud) serial port. I believe it's only the C and E series which provide AIS support
jonic
Well-Known Member
[ QUOTE ]
Having said that, for the price, NASAs AIS radar is hard to ignore.
[/ QUOTE ]
Quite right, and for £219 I couldn't ignore it any longer and bought it today. I have an older radar so will mount it next to that screen as an additional source of info.
Having said that, for the price, NASAs AIS radar is hard to ignore.
[/ QUOTE ]
Quite right, and for £219 I couldn't ignore it any longer and bought it today. I have an older radar so will mount it next to that screen as an additional source of info.
Amphitrite
Well-Known Member
The Nasa Engine is well known not to meet the RS232 specs and therefore it is very difficult to run with a raymarine C or E series. An EasyAIS (not expensive either), together with an AIS-compatible multiplexer if necessary, is the best way to get AIS to a raymarine plotter. Dedicated VHF antenna or antenna splitter is a personal choice both having pros and cons.
Holger
Holger
ParaHandy
Well-Known Member
Re: AIS & MARPA
"You'll also need a fast heading sensor if you want serious MARPA"
ah, you've got a new one? Will Nab Tower stay still for long enough?!!
"You'll also need a fast heading sensor if you want serious MARPA"
ah, you've got a new one? Will Nab Tower stay still for long enough?!!
tome
Well-Known Member
Re: AIS &amp; MARPA
Hee hee, watch this space
I'm evaluating 5 (so far!) top range compasses shortly against a very accurate control for work purposes. Might leak some details here end of June
Hee hee, watch this space
I'm evaluating 5 (so far!) top range compasses shortly against a very accurate control for work purposes. Might leak some details here end of June
hornblower
Well-Known Member
I have ordered E80 thingie with all the bits (will it incude AIS & MARPA?) - am old fshioned handraulic navigator until now.
