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Old 01-24-2013, 09:55 AM   #81
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marinetraffic.com is great, but I would not rely on it for navigation. marinetraffic.com relies on volunteers for for their receiving stations. And ... as they state on their site, the data can be up to an hour old. As I interpret that, there is no guarantee vessels reporting AIS are actually where they appear to be at any point in time..
I'll add to that; There are areas of non-coverage and because volunteers are used for data collection, an area that was covered last week may no longer be covered. For the past several weeks, Savannah, GA has shown no traffic, but a a major port, I' pretty sure ships are still coming and going.

If you are travelling in an area between two ports, there's a good chance this site will not display vessels that might be a hazzard to you.
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Old 01-24-2013, 10:16 AM   #82
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I am not sure what added functionality AIS transponder brings to the SAR situation that a DSC radio doesn't already supply. Can any of the AIS users enlighten me? Both are VHF based so are limited to that range.

Unless you have a DSC equipped portable VHF, neither is of much good when your boat has sunk. And of course the portable has even more limited range. Thus the necessity of an EPIRB for off shore passage making.
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Old 01-24-2013, 11:43 AM   #83
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Some of us have been using it since it became required because of our commercial affiliation...but I still see extremely limited value for my boat and the way I cruise. I have WAYYYYY too many other upgrades to worry about...

But.... it's invariably becoming common in VHF radios so my next radio purchase will most likely bring it aboard.
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Old 01-24-2013, 01:48 PM   #84
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Thanks Rusty. From your description i can definately see the advantage to ais especially in bad weather. Your description also btrings forth a yearning to be out on the sea

Britt
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Old 01-24-2013, 01:58 PM   #85
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I'll add to that; There are areas of non-coverage and because volunteers are used for data collection, an area that was covered last week may no longer be covered. For the past several weeks, Savannah, GA has shown no traffic, but a a major port, I' pretty sure ships are still coming and going.

If you are travelling in an area between two ports, there's a good chance this site will not display vessels that might be a hazzard to you.
Still it can be a useful tool. Radar, Loran, are also not dependable at times. You know, this reminds me of the twin vs. single thread, redundancy is always nice if you have the room and money to spend on them but no substitute for proper maintenance or a sharp eye. I mean seafarers sailed the worlds oceans and inland waterways for centuries before we learned that radar and depth sounders were indispensable.
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Old 01-24-2013, 02:02 PM   #86
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Greetings,
Hold your horses there Mr. 45! Surely you're not expecting 667 posts out of THIS are you?
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Old 01-24-2013, 02:43 PM   #87
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.....Loran, are also not dependable at times. ....
You are right, Loran C is not dependable according to this.

Coast Guard terminates LORAN-C broadcast Coast Guard Compass
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Old 01-24-2013, 03:17 PM   #88
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Still it can be a useful tool. Radar, Loran, are also not dependable at times.
I take it you are not aware that Loran ceased to exist a few years ago?

I don't know if there are classes on marine navigation technology but if there are I'm thinking you should take one before continuing with your quest to figure out what you need.
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Old 01-24-2013, 03:45 PM   #89
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Still it can be a useful tool. Radar, Loran, are also not dependable at times. You know, this reminds me of the twin vs. single thread, redundancy is always nice if you have the room and money to spend on them but no substitute for proper maintenance or a sharp eye. I mean seafarers sailed the worlds oceans and inland waterways for centuries before we learned that radar and depth sounders were indispensable.
My post was a reply to the one about marinetraffic.com, not an actual AIS receiver on board a boat.
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Old 01-24-2013, 04:08 PM   #90
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Greetings,
Hold your horses there Mr. 45! Surely you're not expecting 667 posts out of THIS are you?
.....naw Mr. RT, 667 is ancient history now we are on to bigger and better things

I mean piloting aids are nice to have but they do not substitute in the least bit for a sharp eye at the helm under any circumstances.

Back in October i had an incident while crabbing that i thought was the end of the line for me. I had just dropped a pot when i began to feel light headed, my chest hurt and i thought i was done. I sat down on the transom to keep from falling thinking i was about to pass out and considered my options. The crashing breakers and the sound of the bar was getting closer as i thought of myself passing out then being swept off into the Pacific ocean never to return home again.....Well my daughter used to say because of the crazy things i would do alone that someday i would just disappear never to be found except for my big boots...Maybe this was the time? I noticed that i seemed to be stable sitting but weak so contemplated calling the coast guard deciding instead to just go for it and return to port. I then started the engine only to have it immediately stop a line having fouled the prop. i crawled back finding i could not clear the prop but I managed to haul the pot in and cut the line. I was still without my single main engine so i lay on the deck while planning my next move to ease the strain on my heart.. Since i was functioning sorta ok i decided I needed to do something fast fearing the river current and the ebb tide taking me towards the rocks at the end of the south jetty. I decided to see if the 9.9 merc i had on board would power the vessel against the tidal and river flows .There was a bit of a chop the wind blowing from the north west making the poor little 9.9 strugle. After a few minutes i regained some confidence in my ability to weather this storm single handed deciding i would try and retrieve my pots instead of abandoning them. After retrieving my pots I steered into the channel towards the nearest port speeding along at 1.5kts or less. At this point I had about 2nm to go so i decided to steer towards the south shore realizing i was a hazard to shipping. Just then i noticed a large chip hauler heading towards me at a pretty good clip with my tiny engine doing all it could do. Seemed to me i wasn't moving at all and the big boy was hauling .....in my direction. I again thought of activating emergency services as a feeling of hopelessness engulfed me but decided to just relax, wait, and see what developed. The little motor hummed at my direction with the seas doing their best to send me for sushi across the ocean or into the rocks with the freighter bearing down upon me at a zealous pace. Well I made it across and into port, disembarking with difficulty but able to wobbly walk to my truck. At this point i wasn't sure if i could even drive but i did very cautiously. I managed to make it to a drug store were i purchased some vitamins taking one immediately washed down with a nice warm 9.2% beer. Humm..maybe if i had of drank some beer out crabbing ????.....naw, beer don't go with sushi does it?

A couple of years ago i had had issues i thought were my heart but the doc said it wasn't and that i was fine. I discovered on my own that if i took a certain vitamin called men's one, that the symptoms disappeared. Well a week before the incident above i had left my vitamins in California so i wasn't taking them when this happened. To make a long story short the doc's again said there was nothing wrong with me but i do not miss a single day with the vitamins. Oh, the doc said the vitamins wouldn't help.


anyway everyone, sory for getting side tracked but RT got me started
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Old 01-24-2013, 08:40 PM   #91
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I am not sure what added functionality AIS transponder brings to the SAR situation that a DSC radio doesn't already supply. Can any of the AIS users enlighten me? Both are VHF based so are limited to that range.
DSC only transmits your MMSI, position and a DSC alert message. AIS transmits continuously and sends much more information. Even when not in trouble, your position, bearing, speed, destination, status, callsign, vessel description and is being reported to all around you, as well as the Coast Guard and VTS.
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Old 01-24-2013, 09:03 PM   #92
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DSC only transmits your MMSI, position and a DSC alert message. AIS transmits continuously and sends much more information. Even when not in trouble, your position, bearing, speed, destination, status, callsign, vessel description and is being reported to all around you, as well as the Coast Guard and VTS.
as long as you are in VHF range........but that's true with DSC too....
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Old 01-24-2013, 09:14 PM   #93
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Thanks SS, appreciated.

So, bearing and speed. The MMSI data base the CG has contains the other info relevant for SAR purposes. More/other important detail would be provided with the Mayday you are transmitting right after you activated DSC: people on board and their condition, exact nature of distress, etc. AIS certainly would be an enhancement if your transponder had emergency functionality, though I think its biggest value is in bad visibility situations as an enhancement to radar (yours and others'), rather than SAR.
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Old 01-25-2013, 12:16 AM   #94
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AIS wouldn't be particularly useful where I am at as the large vessels that frequent the area aren't required to have it; tugs, towboats, and fishing vessels. I've been watching siitech and marine traffic for years now (siitech always has more targets). It seems that many of the vessels that do have AIS, still don't have the data fields completed or are incorrect.

Funny enough, the recreational boats I see are usually set up correctly, and even leave it on in the harbour...
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Old 01-25-2013, 12:26 AM   #95
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The AIS information provided by MMSI is quite helpful to us when on the water during poor/no visibility conditions. Knowing the vessel size, type and potential speed well in advance is another safety tool. Not to be known, is the CG has an AIS data base which they follow from many miles away - big brother or helping hand , take your choice.

I've been watching the BC and Washington ferries on AIS from my slip today, all are on time! Even more fun is watching the big ships departing Vancouver or Seattle and entering Straits of Juan de Fuca and those coming the other way. There is an amazing amount of traffic in the PNW cargo lanes.

This has been an interesting thread in that those who don't have AIS don't see the use and those who do have AIS, like it. Kinda like singles vs twins.
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Old 01-25-2013, 12:32 AM   #96
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I've been watching the BC and Washington ferries on AIS from my slip today, all are on time! Even more fun is watching the big ships departing Vancouver or Seattle and entering Straits of Juan de Fuca and those coming the other way. There is an amazing amount of traffic in the PNW cargo lanes.
That is a very good use for AIS. When I can't see out the window to check on the local ferries, I use AIS on my phone. Likewise when I visit my friends in Cordova Bay, I love identifying the ships going by on Haro Strait. I am a ship geek.
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Old 01-25-2013, 01:03 AM   #97
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The AIS information provided by MMSI is quite helpful to us when on the water during poor/no visibility conditions. Knowing the vessel size, type and potential speed well in advance is another safety tool. Not to be known, is the CG has an AIS data base which they follow from many miles away - big brother or helping hand , take your choice.

I've been watching the BC and Washington ferries on AIS from my slip today, all are on time! Even more fun is watching the big ships departing Vancouver or Seattle and entering Straits of Juan de Fuca and those coming the other way. There is an amazing amount of traffic in the PNW cargo lanes.

This has been an interesting thread in that those who don't have AIS don't see the use and those who do have AIS, like it. Kinda like singles vs twins.
did someone mention singles vs. twins??.........I agree and i have learned from this thread. I have concluded like you that it is a useful tool and dosen't appear to be expensive either.
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Old 01-25-2013, 02:48 AM   #98
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That is a very good use for AIS. When I can't see out the window to check on the local ferries, I use AIS on my phone. Likewise when I visit my friends in Cordova Bay, I love identifying the ships going by on Haro Strait. I am a ship geek.
I agree with this. I think the ID aspect, for the pure enjoyment of it, will be a nice thing to have.
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Old 01-25-2013, 06:01 AM   #99
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For those that use Marinetraffic.com , please be aware of certain limitations...to the free version at least.
Many times we will be NOWHERE near where it shows us. Case in point, our chief engineers' wife called the tug and wanted to know why we were only off the New Jersey coast (we had left 4 days prior, heading to the Bahamas). We were actually off of The coast of Florida.
This happens frequently.
A captain I know will unplug his AIS at the dock and move the tug to go grub shopping, get water etc. His supervisor will "see" him on Marine traffic as at the jobsite dock! when he gets back to the job, he re-connects his AIS antenna. Marine traffic is showing the vsl as at the original position.
Keep in mind that these boats use IMO compliant versions of Furuno AIS so it probably not an equipment malfunction. Also, while in New York, we are on the VTS system. So we would know quickly if the AIS wasn't painting the boats signature.
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Old 01-25-2013, 06:49 AM   #100
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........ This has been an interesting thread in that those who don't have AIS don't see the use and those who do have AIS, like it. Kinda like singles vs twins.
Or, Those who don't see a good use for AIS in their particular situation don't have it, and those who have determined that it would be a help in their particular situation have it.

Add to the "have it" group, the ones who find it an interesting toy.
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