Satelite AIS.

[Snowpetrel]

Been tracking my folks boat as the head up the coast of NZ. They have just fitted a normal class B AIS. I am finding that marine traffic seems to show them up fairly regularly via satelite even when they are well away from a base station as long as I zoom in to the aproximate area.

Often the updates are 40 or more minutes out of date, but even so this still seems pretty good.

I dont have confirmation its is them, it just tells me it is a pleasure boat, since I don't have the premium account for $20 per month. But if its going to work this well I might subscribe if they, or someone else I am watching heads offshore. It seems like a cheaper and easier way to get regular position updates than satcomms.

This satellite service seems like it could really justify having a AIS transmitter onboard even offshore in remote areas. I assume in the event of an emergency or search authorities could access this data?

Anyway the point of this post is a heads up if you didnt know about it, and also to find out more about how reliable it is if any of you have been using it, and if there is anyway to help improve your signal to get better sat coverage?

[Snowpetrel]

Here is a picture of the satelite tracking working.

Interesting that it seems to struggle to update in inshore waters. Maybe its because of the land around the vessel? Or maybe the update interval is worse than I thought?

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[sailormed]

It would be easier if the boat just installed a Spot satellite tracking system. It will be cheaper to.


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[Snowpetrel]

Not for a few one off voyages were it might be posible that $20 would cover it quite well. With this system, even the free limited version seems to work reasonably well. And has no extra cost, given they already have AIS onboard.

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[Snowpetrel]

Just looked up the latest spot plans, pretty neat option if you were away for a while. In aussie dollars its looking like around $200 for the spot, and $120 usd per year for a basic tracking plan. So long term its cheaper than a marine traffic type S-ais service, but short term its not.

It seems like some of the extra plans enable you to send text messages, it might be quite a bit cheaper than say the yellowbrick type? I couldnt find info on the number of msgs allowed.

Coverage doesn't seem to be worldwide. Big gaps in the pacific ocean by the looks of it.

[StuM]

My preferred solution is a Delorme InReach. It cost me about $6 a month on standby and about $30 a month when I activate it for a trip. Better coverage that the spot and I can send and receive text messages if I need to.

Anyone can track me if I give them the Delorme mapping URL.

[hoppy]

Originally Posted by sailormed

It would be easier if the boat just installed a Spot satellite tracking system. It will be cheaper to.


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Spot is rubbish for cruising.....

There is no speed data on the tracking site, it only shows a day or two tracking on the map and the coverage is not world wide.

Yellow brick is way better and I'm guessing so is the Delorme as both use iridium


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[Time2Go]

My Delorme InReach has worked flawlessly for the past 2 years in Europe as well as in US. Great piece of kit.
Tracks every 30 minutes, two way text, now with weather reports for an extra
1.00 US per report (data by OCENS). 25.00 US a year to keep it active
Then 35.00 per month when in use
Plus it's a back up GPS
Cheers
Neil

[Snowpetrel]

I do like the Delorme. I think if I was headed offshore at the moment either that, or the YB would be high on my list. In aussie the plans are not as good as the US unlimited plan which seems like a bargain at usd $60 or $70 per month. The best aussie plan at the moment has only 200 free txts.

The base unit is good value but still costs aud$500 or so.

I guess both the spot, YB and Delorime also work in an abandonment situation and are stand alone, which is another plus.

Saying that the s-ais is virtually free if you already have AIS. And if you do just one offshore voyage or even just an isolated coastal voyage which is out of cell phone range it gives people a way to see where you are pretty cheaply.

[hoppy]

Does S-AIS reliably work with lower powered class B units?


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[El Pinguino]

According to this ( posted on another thread ) the answer is 'yes'.
http://www.sarsat.noaa.gov/BMW%20201...ng_21May10.pdf

[hoppy]

Originally Posted by El Pinguino

According to this ( posted on another thread ) the answer is 'yes'.
http://www.sarsat.noaa.gov/BMW%20201...ng_21May10.pdf

Not necessarily....

There is a limitation with AIS of how many transmissions can be received and it's possible that given the vast areas that S-AIS satellites cover, they could need to filter out class B transmissions and only report class A and SART transmissions....

We need someone to stump up the cash to pay for access to S-AIS and track come cruisers and their class B units

[hoppy]

An example of why I don't think Spot is good for cruisers

Boaty's current atlantic crossing. The Spot page only shows 50 positions at a time, so you have to page through his track. Spot's information for each position report is only of limited use for people wanting to follow a journey


ESN :
0-2441613
Type :
TRACK
Latitude :
40.3165
Longitude :
-38.02884
Time :
28/06/2016, 10:53:16
Battery State :
GOOD

SPOT Shared Page


On the other hand, this is my pissing around in Greece YB track. It can show on a single page the whole journey. The date ranges visible are defined by the user. By defaut it is currently showing every position report since the start of 2015. Viewers can select the other date ranges I have defined (click on date, top left corner

This is the information reported each time.

25/Jul/2015 @ 03:30:00 EEST
38° 32.22N, 020° 13.19E / Course: 170° @ 3.9 knots
27°C

If I was to hardwire it to the boat, I can even transmit some NMEA data as well

https://my.yb.tl/Jessabbe/

I'm sure most sailors following family or friends from home will appreciate the additional information YB provides.

[El Pinguino]

Originally Posted by hoppy

Not necessarily....

There is a limitation with AIS of how many transmissions can be received and it's possible that given the vast areas that S-AIS satellites cover, they could need to filter out class B transmissions and only report class A and SART transmissions....

We need someone to stump up the cash to pay for access to S-AIS and track come cruisers and their class B units

Hmmmm... well in that link they say than can monitor 1000's at a time and offshore yachts would be a small poprtion of the total
"Each satellites continually receives AIS signals from all ships in its footprint (1000‟s of ships !)"

Also Ben's parents only have Class B

And in conclusion.... go into MarineTraffic and filter out everything but 'pleasure craft'. This is what I just found for the central south pacific...NZ bottom left.
I'm sure they are not all super yachts with Class A.

[Littlechay]

AIS has a major advantage over SPOT, Yellow Brick etc. in that it tells ships that are about to run you down that you are there, provided that they have AIS, and also alerts you to them, same proviso. And it gets picked up by the satellite AIS systems so you get two functions in one go.

I found that my class B AIS shows up fairly reliably in Polynesia on https://www.yit.nz/ when I looked at times when I had WIFI.

The satellite AIS trackers are becoming more reliable and more accessible as the technology matures.

For family and friends tracking I don't plan on doing any more than a daily (ish) update and only on ocean crossings to YOTREPS, occasionally I also fill in some postcard text too - also totally free.