Hi Group

I've heard you had a discussion about AIS for leisure crafts (eg sailboat),
so I have just started "listening" to this news group.

Could you "kick-start" me on the subject?

Thanks
/Boerge

Børge Wedel Müller wrote:

I've heard you had a discussion about AIS for leisure crafts (eg sailboat),
so I have just started "listening" to this news group.

Could you "kick-start" me on the subject?

Good timing. I just installed a Nasa Marine "AIS Radar" on Voyager this
week (see http://www.nasamarine.com/). I don't think they're available
in the States but was in England on business so picked it up there.
Price was 230 pounds, including VAT.

It takes 12 volts, a VHF antenna, and NMEA from the GPS in, and plots
on a radar-like screen the position of all vessels transmitting AIS.
The rule is that all ships over 300 GRT must have AIS.

On Voyager we sail very short-handed so a watch is always a headache. I
have an old Combi Watchman radar detector, but have found that over
half the ships we encounter at sea do not have their sets on (you can
see their antennas not rotating). We use radar sometimes with an alarm
set, but that sucks an awful lot of power. And, it can't tell the
difference between a ship and a squall, and too often there's rain
squalls everywhere, making the alarm feature problematic.

Here in Baltimore harbor the AIS immediately found and plotted two
dozen ships. You can toggle to a specific ship and it shows the
vessel's position, name, MMSI, course, speed and status. The alarm,
when enabled, beeps loudly when there's a ship within a user-specified
range of the yacht.

The gear works great. My biggest complaint: it uses a brain-dead PIC
micro without enough memory to remember all of the info about the ships
it tracks. So when you toggle to a new ship there's a delay - sometimes
a couple of minutes - while it waits for an AIS transmission from the
ship.

The device is rated at 80 milliamps draw, though I measured 130ma.
Still, that's nothing. I'm anxious to try it at sea.

It does need its own VHF antenna - the higher the better the range.
Voyager is a ketch so the antenna lives atop the mizzen.

AIS appears to be a real boon for short-handed watchkeeping.

Jack
www.ganssle.com/jack

"Børge Wedel Müller" wrote in news:4392f876$0
:

Could you "kick-start" me on the subject?


Look at the Google cache for the posts.

The sooner AIS is in all boats that can't turn quickly and must be in a
channel, the better.

This idea isn't "new". Ham radio operators have been using a GPS to VHF
or HF link called APRS, which is a much simpler protocol, for many years.

It was invented by Bob Bruninga, WB4APR, at the US Naval Academy to track
lost midshipmen in the Academy's small boats.
http://web.usna.navy.mil/~bruninga/aprs.html

http://www.aprs.net/
http://www.findu.com/ Let's you watch APRS from the internet
http://www.winaprs.org/

But, of course, this would be too cheap to put in a boat, no matter how
well it works. We have to have some outrageously-expensive, proprietary
system controlled by some patent holders, which really slows
implementation and leaves most small boaters unable to afford the
technology.

The AIS companies have live portals on the net to sell their wares:
http://www.aislive.com/AISLivePortal/
http://www.sealinks.net/World.htm
http://www.tsr-as.dk/ais.html even one in Denmark!
http://www.uais.org/LiveAIS.htm
http://www.dublinport.ie/
http://www.panbo.com/yae/archives/001018.html of course like charts,
we'll try to sell it to you.
http://www.lrfairplay.com/services/i...dvertising.htm
You'll need to have spam on the webpage, of course.

Just the ability to see around-the-bend in the river is worth having at
least an AIS receiver aboard. But, he won't see YOU unless you get a
full transponder.

Small boats at sea have always been at risk because, even with their
radar reflectors, they are such a tiny target, so low to the sea clutter,
most ships cannot see them, especially in close to the ship where the
ship's radar shoots right over the top of their masts when it's needed
most. AIS transponding completely solves this problem. The ship has a
constant view of your position, course, speed, who you are, what you are
for the lookouts (if there are any), even if your small boat is in the
bottom of the troughs. It's an amazing leap forward in safety-at-sea,
but will make small boats even MORE dangerous as the ships' watches rely
more and more on the new AIS display in front of the helmsman. Unless
you conform and buy a transponder, with him staring at his computer
screen for a lookout, he'll drive right over you.

On 4 Dec 2005 06:44:44 -0800, "
wrote:


Good timing.

Jack
www.ganssle.com/jack

Thanks for the info and review... on AIS

I went to your web page - very nice and informative -Jacks musings
blog and dual monitors and all.

And your PDF article on USB scopes also worthy although I didnt have
the time to read your 4 books or other 500 articles but the rebuild of
your sail diesel was interesting...

Hey Larry you might be interested in Jacks links www.ganssle.com


MIC

AIS as well as giving CPA and TCPA does give the name and call sign of the
ship. This allows the sailer the option of calling the ship by name on the
radio which is more likely to get a answer. It also gives a much bigger
window to take evasive action. Line of sight from a mast mounted VHF antenna
on the sailboat to the antenna on a Deepsea ship is a great distance. My
guess is you will *see* anything within 40-50 miles. Thats close to a couple
of hours notice for the fastest containership.

BTW Panbo (http://www.panbo.com/yae/archives/cat_ais.html) is reporting
Class B AIS transponders for $500 (maybe).

SaltAir

" wrote in
oups.com:

Here in Baltimore harbor the AIS immediately found and plotted two
dozen ships.

Is any bureaucratic entity transmitting from shore all the bouys,
obstructions and notice-to-mariners yet? We're way behind on AIS in the
States, how awful. I've talked to a few Coastie techies and I was more
instructional about AIS than I got answers to what CG is doing to get the
fixed obstructions on the air.

(Mic) wrote in :

Hey Larry you might be interested in Jacks links www.ganssle.com


Thanks, I'll take a look.

Anyone noticing or knowing about AIS fixed obstructions/bouys/etc. being
transmitted from shore stations in their area, please let us all know what
you know...thanks, too!

On Sun, 04 Dec 2005 20:45:40 -0500, Larry wrote:

Is any bureaucratic entity transmitting from shore all the bouys,
obstructions and notice-to-mariners yet?

========================================

The Navtex broadcasts have much of this. You can receive them on an
ICOM802 with a Pactor, Airmail and a laptop.

wrote:
Børge Wedel Müller wrote:

I've heard you had a discussion about AIS for leisure crafts (eg
sailboat), so I have just started "listening" to this news group.

Could you "kick-start" me on the subject?

Good timing. I just installed a Nasa Marine "AIS Radar" on Voyager
this week (see http://www.nasamarine.com/). I don't think they're
available in the States but was in England on business so picked it
up there. Price was 230 pounds, including VAT.

It takes 12 volts, a VHF antenna, and NMEA from the GPS in, and plots
on a radar-like screen the position of all vessels transmitting AIS.
The rule is that all ships over 300 GRT must have AIS.

On Voyager we sail very short-handed so a watch is always a headache.
I have an old Combi Watchman radar detector, but have found that over
half the ships we encounter at sea do not have their sets on (you can
see their antennas not rotating). We use radar sometimes with an alarm
set, but that sucks an awful lot of power. And, it can't tell the
difference between a ship and a squall, and too often there's rain
squalls everywhere, making the alarm feature problematic.

Here in Baltimore harbor the AIS immediately found and plotted two
dozen ships. You can toggle to a specific ship and it shows the
vessel's position, name, MMSI, course, speed and status. The alarm,
when enabled, beeps loudly when there's a ship within a user-specified
range of the yacht.

The gear works great. My biggest complaint: it uses a brain-dead PIC
micro without enough memory to remember all of the info about the
ships it tracks. So when you toggle to a new ship there's a delay -
sometimes a couple of minutes - while it waits for an AIS
transmission from the ship.

The device is rated at 80 milliamps draw, though I measured 130ma.
Still, that's nothing. I'm anxious to try it at sea.

It does need its own VHF antenna - the higher the better the range.
Voyager is a ketch so the antenna lives atop the mizzen.

AIS appears to be a real boon for short-handed watchkeeping.

Jack
www.ganssle.com/jack

Don't forget to reclain the VAT Jack!

"Larry" wrote in message
...
"Børge Wedel Müller" wrote in news:4392f876$0
:

Could you "kick-start" me on the subject?


Look at the Google cache for the posts.

The sooner AIS is in all boats that can't turn quickly and must be in a
channel, the better.

This idea isn't "new". Ham radio operators have been using a GPS to VHF
or HF link called APRS, which is a much simpler protocol, for many years.

It was invented by Bob Bruninga, WB4APR, at the US Naval Academy to track
lost midshipmen in the Academy's small boats.
http://web.usna.navy.mil/~bruninga/aprs.html

http://www.aprs.net/
http://www.findu.com/ Let's you watch APRS from the internet
http://www.winaprs.org/

But, of course, this would be too cheap to put in a boat, no matter how
well it works. We have to have some outrageously-expensive, proprietary
system controlled by some patent holders, which really slows
implementation and leaves most small boaters unable to afford the
technology.
....
If I remember correctly the AIS inventor , Håkan Lans, was forced to give up
his patent rights to get the system into the standards. I might be mixing it
it up with the corresponding system and standards for air traffic.
/Lars J